segunda-feira, 27 de março de 2017




On my CV:
After a graduation in medicine I made my M.S. in philosophy at the UFRJ (Rio de Janeiro), Ph.D. at the University of Konstanz (Germany) and post-doctoral works at the Hochschule für Philosophie (Munich) and at the universities of Berkeley, Oxford, Konstanz, Göteborg, and at the École Normale Supérieure. 
My main articles published in international journals were collected and better developed in the book Lines of Thought: Rethinking Philosophical Assumptions (Cambridge Scholars Publishing, 2014). Also from interest may be a short theory on the nature of philosophy in the book The Philosophical Inquiry (UPA, 2002). Presently I am writting a book aiming to recuperate the credibility of the old orthodoxy in analytic philosophy of language. This book, to be called Philosophical Semantics, will be also published by CSP in 2017. 

Presently I am full professor at the Department of Philosophy of the UFRN, Natal, Brazil. I probably have a light degree of autism, what I believe to add some points to my curriculum.

Advertisement of some published books (see Amazon.usa):


 Draft H of a text belonging to the book Philosophical Semantics to be published by CSP in 2017. The english wasn't corrected yet.

Appendix to Chapter II


Die Probleme, die durch ein Mißdeuten unserer Sprachformen entstehen, haben den Charakter der Tiefe. Es sind tiefe Beunruhigungen; sie wurzeln so tief in uns wie die Formen unserer Sprache, und ihre Bedeutung ist so groß wie die Wichtigkeit unserer Sprache.
[The problems arising through a misinterpretation of our forms of language have the character of depth. They are deep disquietudes; they root as deeply in us as the forms of our language, and their significance is as great as the importance of our language.]

La filosofia è l'arte di creare molti problemi di alcune poche soluzioni.
[The philosophy is the art of creating many problems out of some few solutions.]

Although exceedingly original and challenging, Saul Kripke’s philosophical application of modal logic to problems of reference seems to me to be burdened by a disturbing web of confusion. Since many would disagree, I will justify myself through a critical discussion of his article ‘Identity and Necessity’ (Kripke 1971), which precedes the more developed views defended in his book Naming and Necessity (Kripke 1980), since that short article takes the central ideas directly from the oven. The paragraphs summarizing Kripke’s article are in italics, in order to distinguish them from paragraphs containing my own comments. After my comments on this article, I provide an Addendum containing a series of brief criticisms of ideas from Kripke, Hilary Putnam, Gareth Evans, David Kaplan, Tyler Burge and John Perry, as part of my project of debunking the metaphysics of reference/meaning.

Kripke begins by considering the modal argument for the necessity of identity statements. This argument can be summarized as follows. Given the principle of the indiscernibility of the identical, according to which (x) (y) ((x = y) → (Fx → Fy)), and given the principle of identity, according to which (x) (x = x), we can conclude that if the property F is to be necessarily applied to x, then y must also have this property. That is, it is necessary that y equals x. In symbolic notation, (x) (y) (x = y) → ((x = x) → (x = y)), namely: (x) (y) (x = y) → (x = y).
   This apparently inconsequential formal result leads Kripke to the bold conclusion that identities between proper names are necessary. We know this by universal instantiation □(x = y) → □ (a = b). That is, if a and b are real names and a = b is a true identity, then this identity is necessarily true. This would concern identities like ‘Hesperus is (the same as) Phosphorus’ and ‘Cicero is (the same as) Tulius’: they must be necessarily identical. Further, if F and G are theoretical predicates, defined as essential designators of properties, if they form a true theoretical identity of the form (x) (Fx = Gx), then this identity is also necessarily true. That is why identities like ‘Heat is molecular motion’ and ‘A state of mind is a physical state,’ if true, are necessary.
   Kripke recognizes that identities between names and between theoretical identities have generally been considered contingent. There seems to be good reasons for this. Consider the statement ‘Hesperus is Phosphorus.’ Since Hesperus is Venus seen at dusk (evening star), and Phosphorus is Venus seen at dawn (morning star), it was an important astronomical discovery that they are actually the same planet, as Frege noticed. Therefore, this seems not to be a necessary, but rather a contingent empirical truth with the modal form ◊ (a = b). The same applies to theoretical identities such as ‘Heat is molecular motion.’ This identity was a scientific discovery and could be false, because if caloric theory (the theory that heat consists of a self-repellent fluid called caloric) were correct, heat would not be molecular motion. This seems to be a contingent statement, since it clearly could be otherwise.
   Kripke’s thesis, however, is that contrary to appearances, all these identities, despite having been learned a posteriori, are necessary, even if they do not seem to be: they are necessary a posteriori identities. To reinforce his thesis he introduces an important distinction between the rigid designator, here defined as a term that refers to the same object in any possible world in which this object exists or would exist, and the non-rigid or accidental designator, which can refer to different objects in distinct possible worlds (1971: 146). Proper names and terms of natural species are rigid designators designating the same object in different worlds. Most definite descriptions, by contrast, are accidental designators, designating different objects in different possible worlds. Hence, if we have an identity in which the identity symbol is flanked by proper names, this identity is necessarily true if true at all, considering that these proper names, being rigid, must have the same bearers in any different possible worlds where their bearers exist.

It is clear that a mathematical term can be seen as a rigid designator, insofar as it does not depend on how the world is. But is it really impossible for proper names to be other than rigid designators? In an attempt to show that sometimes they could be accidental designators, we can imagine the following. Suppose it were discovered that shortly after G. W. Bush’s early childhood an extra-terrestrial being took possession of his body, assumed his identity and impersonated him, subsequently being elected president of the United States and performing all actions attributed to him. In this case, wouldn’t the proper name ‘G. W. Bush’ be used unknowingly to refer to this extra-terrestrial being instead of to the son of Barbara and George Bush, born on 6/7/1946, becoming in this way an accidental designator?
   The truth is that the idea that a proper name is a rigid designator would resist to such objections. According to Kripke’s views, the reference of a proper name is due to an act of baptism. But this means that the true W. G. Bush, as the bearer of the rigid designator ‘W. G. Bush,’ would long since have ceased to exist. On the other hand, the embodied extra-terrestrial being, whose true name was, say, Gkw9, would have had another baptism on some remote day, and the name W. G. Bush (in fact here a mere nickname of Gkw9) would apply to this same extra-terrestrial being in any possible world where he existed, satisfying the property of being a rigid designator. We simply have two different rigid designators, two different proper names.
   Applying my own theory of proper names, as summarized in the appendix of chapter I, the results would be the same. According to this theory, the proper name’s bearer is the object that satisfies its identification rule. What this identification rule requires is that this object sufficiently and better than any other satisfies the inclusive disjunction of the fundamental description-rules, which are the localizing and the characterizing rules. For the adult W. G. Bush (as Gkw9), for instance, the localizing description includes his earlier spatio-temporal career on another planet before his embodiment on the Earth, and after this his Bush impersonation in Washington (as US president) and his subsequent life. On the other hand, the characterizing description would include his main accomplishments, including his election as 43rd president of the USA, leading the country after 9/11, beginning wars in Iraq and Afghanistan, and also his life as the being who earlier on a distant planet had the career of Gkw9... In every possible world where the identification rule is satisfied, W. G. Bush (as Gkw9) would exist. Hence, the identification rule for the name is also a rigid designator. Something of the kind could be easily established also for the child really named W. G. Bush, born on 6/7/1946… also making this name a rigid designator by satisfying its own identification rule.
   In addition, Kripke believes he has warranted the necessity of the identity between proper names by having discovered some radical metaphysical difference between proper names, on the one hand, and definite descriptions, on the other. What his words suggest is that a proper name would reach its reference without intermediaries by means of a direct (in my view purely magical) relation instituted in the act of baptism. For him, this act does not really depend on any property of the object, notwithstanding in some inexplicable way allowing the post-baptismal production of external causal-historical chains between speakers; chains that in the end allow any speaker who utters the name as last link of them to refer to the bearer of the name.[1] A definite description, on the other hand, is only an accidental designator: it would refer to different objects in different possible worlds, supposedly because it has what John Stuart Mill called a ‘connotation,’ defined by him as ‘the description’s implication of an attribute that the object may have’ (1881, I, Ch. 2). Using Kripke’s example, this would be the case of the definite description ‘the inventor of bifocals,’ which in our world refers to Benjamin Franklin, but could refer to any other person and even to no person in different possible worlds, while the proper name ‘Benjamin Franklin’ always refers to the same person in any possible world.
   In my view, Kripke’s explanation for this dichotomy, suggesting an impenetrable difference in the nature of each referring process, is as mysterious as dispensable. The only way to really explain the dichotomy is by appealing to the already exposed meta-descriptivist theory of proper names (Appendix of Chapter I, sec. 7, 8), which gives an adequate justification for the contrast between the rigidity of proper names and the accidental character of their associated definite descriptions. There, what I have shown that descriptions are not rigid only as far as we compare them with the reference of the proper names to which they are associated. After these explanations the idea of a rigid designator, at first seemingly so original, shows itself to be nothing but the technical spelling of the trivial idea that a proper name must in all circumstances (possible worlds) refer to its own bearer.
   Furthermore, I agree with the idea that the necessity of the rigid designator is always the result of de dicto conventions. The reason is that I think that John Searle’s has saw the kern of the problem. According to him beliefs are de re in the sense that they refer to real objects. The so-called de re beliefs are only a sub-class of the de dicto beliefs, so that there is no irreducible de re belief. Although there is a class of beliefs whose explanation depends on contextual characteristics, one should not equivocally conclude that such characteristics cannot be entirely represented as part of the intentional (mental) content! The true difference between beliefs called de dicto and de re turns out to be a mere difference between reports. In a de dicto belief like ‘Ralf believes that the man with the brown hat is a spy,’ we commit ourselves only to the report of Ralf’s belief. In a de re belief like ‘About the man with the brown hat, Ralf believes he is a spy,’ we commit ourselves also to the existence of the man with a brown hat (Searle 1983: 208-220). In this sense there is no reason why should not be both at the bottom de dicto beliefs. Now, if we reject irreducible de re beliefs, we reject the kind of metaphysical de re necessity assumed by Kripke.
   The neo-descriptivism I have proposed makes a proper name a rigid designator because some combination of descriptions that allows its reference in accordance with its identifying rule must be satisfied in any possible world where the proper name has a bearer. But the reason is not metaphysical. It is simply because the identifying rule defines what any bearer of the proper name can be. Now, considering identity between different proper names, we have here two clearly different cases. The first is the following:
(a)   Two different proper names of the same object have different identifying rules that identify their bearer under different guises, under different ways of presentation, simply because they emphasize different perspectives in which different descriptions or groups of descriptions are satisfied. In this case, even if they are rigid designators, we cannot without further information know that they refer to the same object in all possible worlds, and it may be an empirical matter to decide if these two different rigid designators refer to the same object or to two different objects. We still do not know whether the identifying rules of two names are part of a common identifying rule. Consequently, in a first stage an identity statement of the kind a = b would be contingent a posteriori. The modal form of the identity can be only formulated as ◊ (a = b), what is a too rough approximation.[2] This was the case before the more developed astronomy made us sure that the morning star is the evening star…
The second is the following:
(b)  After many and varied empirical experience we establish a convention, a rule according to which the different ways of presentation, the different identifying rules are constituents of one only more complex identifying rule that includes both anterior rules, each of them emphasizing a different aspect or mode of presentation of the same object. In this case, however, what we in the end have is one only rigid designator able to identify the same object in any possible world even if under different guises. The identity resulting from the newly established convention will be necessary a priori. Its modal form will be □ (a = b). We see that in no moment of this process do we need to resort to a Kripkean necessary a posteriori identity, except if we confuse the a posteriority of (a) with the necessity of (b), as Kripke seems to do.
Only to illustrate the point: there is a way to express Frege’s insight according to which ‘Afla = Ateb,’ in which Afla is the same mountain as Ateb, even though explored from a different complementary perspective, which gives these names different but complementary senses or modes of presentation. However, someday explorers may ask themselves whether Afla is Ateb. At first, they see this identification as a contingent matter: probably Afla is Ateb. After they reassure themselves that they do indeed refer to the same mountain, the more complete identity sentence will be considered to have the implicit form ‘Afla-[Ateb] = Ateb-[Afla].’ That is: Afla and Ateb express rules numerically identifying the same object, simply because they are blended in the formation of one and the same rigid identifying rule, applicable to each side of the same mountain under a different semantic guise. In the first moment, ‘Afla’ and ‘Ateb’ are considered probable de dicto rigid designators, and in the end they are considered necessary de dicto rigid designators. If they are also metaphysically de re rigid designators is something that only God has the powers to know.

Kripke also considers the problem of apriority. A priori truths are those that we can know without appealing to experience. Many consider the necessary and the a priori to be equivalent. However, the concept of necessity is for him metaphysical about how the world must be – while the concept of a priori is epistemic – about how we know the world. Kripke thinks that the two classes are not equivalent. Consider, he writes, Goldbach’s conjecture, which states that any natural number is the sum of two primes. It may be a necessary truth without the possibility of our knowing it a priori. In this case, it would have metaphysical necessity.

The claim that necessity is metaphysical while apriority is epistemological is questionable. This distinction would be justified only if there were indeed metaphysical de re necessities, as Kripke believes, since a de dicto necessity would follow from a more trivial conventionally established apriority, even if rooted in experience. Moreover, the existence of metaphysical de re necessities in the supposed sense is something that goes beyond our cognitive faculties, since our empirical knowledge is inherently fallible – a point that has been insistently emphasized by philosophers of science, from C. S. Peirce (1991, Ch. 7) to Karl Popper (1989, Ch. 10). Under this perspective, the most we can do is to postulate empirical necessities by accepting the most deeply entrenched[3] and strongly inductively grounded regularities as natural laws (Tugendhat 1983: 253; Mackie 1974). We cannot speak of a necessity of a natural law going beyond this well-grounded postulation, since to prove this metaphysical necessity we would need absolute knowledge – something that our epistemic fallibility makes impossible. Therefore, the so-called necessities of natural laws and what follows from them are nothing but a result of a well-grounded decision to treat them as necessary, and since this decision is well-grounded we have the right to expect (pace Armstrong[4]) that they will resist counterfactual situations. These are necessities in a weaker sense of the word, for sure. However, once we postulate them as necessities, we have a right to treat them as what they are: rules of our own conceptual system. This is why we constantly use derived statements of necessity like ‘It is necessary to have fire to light a candle.’ Anyway, such empirical necessities can be identified with practical certainties, once we see that the latter are treated as certainties because we can grant them a sufficiently high degree of probability.
   Finally, what remains from the unknowably real objective essence responsible for the ‘metaphysical necessity’? In my view it still has a function in the form of what Kant has called an ideal of reason. A normative concept (whose supposed reference is impossible to be experienced), made to offer a horizon able to motivate our investigation. It can justify our approximations of truth, serving as ideal model for our comparison between these approximations, allowing us to establish comparative degrees of truthfulness between our judgements. In this context, the idea of a ‘real essence’ serves as a heuristic tool, even if it cannot be a true object of reference. We hold it as if it were something objectively necessary and its justification resides in the pragmatic success of our procedures lead by these ideals.
   If this empiricist analysis of necessity is correct, as I believe, one could suggest a broad distinction between two main kinds of necessity, both of them with essentially epistemic (non-metaphysical) import:

(i)            Formal necessities. Those are the necessities that we find mainly in logic and mathematics and in definitional sentences (like ‘brothers are male persons with the same parents’), which can often be easily shown to have the form of tautologies. Their statements are analytic and their negations are contradictory or inconsistent.
(ii)          Empirical necessities. These are a posteriori reached necessities, which once obtained are simply assumed or postulated as necessities. This is a weaker but very common sense of the term that presupposes the truth of a theory and system of beliefs in which it is inserted (like the nomothetic necessity expressed in a statement as ‘necessarily V = ∆P/∆t (assuming traditional kinematics)’). Under the presupposition of the theory and the system of beliefs in which they occur, they can be seen as analytic and their negation is contradictory or inconsistent.

Wittgenstein has grasped the last point. He would classify many of these last, empirically rooted necessities, as ‘grammatical rules’ – rules grounding a useful linguistic practice (1984a). Here is his suggestion, in which we read the word ‘rule’ as referring to a priori propositions:

Every empirical proposition can serve as a rule if it is fixed as the immovable part of a mechanism, in such a way that the entire representation revolves around it, making it part of a system of coordinates independent of the facts. (Wittgenstein 1984e part VII: 437)

Since they are postulated, empirical necessities do not has the warrant of conventional necessities and it may be doubtful whether is possible to establish a sharp delimitation between both.[5] In fact, I believe that this insight lead us again to the two proposed ways to read identity statements of the kind a = b.
   To begin with, consider the first of Kripke’s examples: (i) ‘Hesperus is Phosphorus.’ In accordance with the suggested analysis, it can be read as:

(a)  A contingent a posteriori statement, broadly understood in relation to our unstable overall system of beliefs. In this case, (i) means (i-a): ‘(Contingently, depending on what experience has shown until now) Hesperus = Phosphorus.’ Statement (i-a) isn’t yet seen as analytical and its negation is seen as reasonable.

It was so when the Babylonians discovered that Hesperus is Phosphorus. They could follow Venus trajectory during the night, they could note that as an internal planet it is always near to the sun, etc. However, at first they were not sure of this identity. It had the modal form of a possible (in fact very probable) identity: ◊ (a = b). Even today, we have the right to hold this doubt, when we oppose the identity with our in principle changeable overall system of beliefs.
   The second way of interpreting the identity is when we establish a conventional rule warranting us that a and b, if they refer, they refer to the same object in any possible world, that is, we postulate that □ (a = b). In this case (i) can be read as:
(b) A necessary a priori identity statement – as an element of the subsystem of beliefs that constitutes our astronomical knowledge, assuming the truth of this subsystem. In this case (i) means (i-b): ‘(Assuming our present astronomical knowledge) Hesperus-[Phosphorus] = Phosphorus-[Hesperus].’ The identification rules are blended in one only, though with different guises. Statement (i-b) is seen as analytical and its negation contradictory or inconsistent.

Consider now (ii) ‘Heat is molecular motion (more precisely: molecular kinetic energy).’ This identity can be read as:

(a)   A contingent a posteriori statement, since understood in relation to our unstable overall system of beliefs. In this case (ii) means (ii-a): ‘(Contingently and in accordance with what experience has shown until now) heat in gases = overage molecular kinetic energy.’ The identity is believed, but it isn’t yet seen as conventional; (ii-b) isn’t yet seen as analytical and its negation is still seen as reasonable.

This would be the case in the last half of the 19th century, as the chemists were unsure about the real cause of heat in gases. The identity had the modal form ◊ (a = b), in fact a very probable possibility. Even today, the remote possibility that heat in gases isn’t the kinetic energy of its molecules cannot be absolutely eliminated. Anyway, we can postulate the truth of the kinetic theory of gases and in this way come to the modal form □ (a = b), so that (ii) will be read as:

(b)  A necessary a priori (analytic) statement – if it is read as an element of the subsystem of beliefs that constitutes the kinetic theory of gases, assuming the truth of this subsystem. In this case, (ii) means (ii-b): ‘(Assuming the truth of kinetic theory of gases) heat in gases = overage molecular kinetic energy.’ Here the ascription rules for the terms flanking the identity sign are blended in one only rule that points to an identity under different semantic guises. (One could say with Wittgenstein that the statement is here hardened, becoming an immovable part of a mechanism.)

Heat (as temperature) is in this case understood based on the general acceptance of the kinetic theory of gases, as a kind of abbreviation of ‘molecular mass-motion,’ what once accepted does not require experience to be seen as true. The rule is only one, with two different guises, one named ‘heat in gases’ and the other named ‘overage molecular kinetic energy.’ (See Ch. IV, sec. 23-26)
   As it was to expect, Kripke blends the a posteriori character of the first reading of these statements with the necessity of their second readings, arriving to an illusory necessary a posteriori.

   As for Goldbach’s conjecture, the fact that it may be a necessary truth without our being aware of it does not mean that in this case the suggestion that any natural number is the sum of two primes is not an a priori truth, since it can also be an a priori truth without our being aware of it. It can be necessary but unknown as much as a priori and unknown. Moreover, if it happens that we never discover its truth a priori, we will also never discover its necessity. And it is not impossible that someone will find a proof of this conjecture, finally giving to it the cognitive status of a theorem with a priori necessity. Indeed, it is because mathematicians (pace Gödel’s theorem) hold as a heuristic rule that it is possible to reach such an a priori necessity that they still insist on searching for a proof.

The most striking and revealing example of a necessary a posteriori statement introduced by Kripke is that of the wooden lectern in front of him. It starts with the question: could this lectern have consisted, since the beginning of its existence, of ice from the Thames? Certainly not: It would be a different object. Thus, the statement ‘This lectern, if it exists, cannot be made of ice,’ is a necessary truth known a posteriori. Lecterns are usually not made of ice. This lectern seems to be made of wood, and it is not cold. Hence, it is probably not made of ice. Of course, this could be a delusion. It could actually be made of ice. But that’s not the point, writes Kripke. The point is that given the fact that the lectern is not made of ice, but of wood, one cannot imagine that it could be made of ice. Given the fact that it is not made of ice, he concludes, it is necessary that it is not made of ice. More precisely: being P = ‘This lectern is not made of ice,’ and considering that we know both, the a priori truth that ‘If P then P’ and, from empirical research, that P is true... Kripke constructs the following argument, applying a modus ponens:

     1  P □P

It is therefore necessary that the lectern is not made of ice, although this is only known a posteriori, by empirical research. The statement ‘This lectern is not made of ice’ is a striking example of a necessary a posteriori!

Unfortunately, there is a well-hidden mistake in Kripke’s argument. It concerns the epistemological status of P in the second premise. In this premise, the truth of P is affirmed in complete disregard for the fact (earlier confusingly indicated by him) that P, like any empirical statement, can only be known to be true by inevitably fallible epistemic subjects. However, if this is so, P can in principle be false. In order to show my point clearly, I first need to specify that a statement is practically certain if it is sufficiently likely to be true that the probability of its being false may be ignored. This is usually the case when we can assign to the statement a probability very near to 1 of being truth.[6] On the other hand, we specify a statement to be absolutely certain if it simply cannot be false, having a probability 1 of being true: it is necessarily true. Considering this, we can instead say that statement P of the second premise should be more precisely written as (2’): ‘It is practically certain that P (that this lectern is not made of ice).’ Indeed, (2’) must be true because we know this. However, only God – the infallible and omniscient epistemic subject – could know with absolute certainty the truth of statement P (that is, would be able to assign it the probability 1). Only God, the infallible knower, could know for sure the factual existence of P. He would in this way give the state of affairs described by P a truly metaphysically de re necessity. Unfortunately, we cannot appeal to God in this matter… All that we can know is that P is practically certain in the already stated sense that assuming all available information is sufficiently likely to be accepted as true. This must be so, once we accept the fallibility of our empirical knowledge, which cannot be absolute.[7] (Always possible is a radically sceptical scenario in which Kripke believes he is standing before a hard wooden lectern, as indicated by all available testimony and after doing all possible empirical research, even though the lectern is nevertheless really made of ice[8]).
   Assuming this, consider Kripke’s premises again. First, it is fully acceptable that given the fact that P, then P follows by necessity. That is, what P → P says is ‘If it is really the case that P, then it is necessary that P,’ and this, I concede, is a logical truth. However, what the antecedent of P → P requires is that P implies □P only under the assumption that P is true, but the truth here must be absolutely certain, since only the absolutely certain truth would be able to warrant the necessity of the consequent, a certainty that is only knowable by God’s omniscience. Hence, the most complete analysis of premise (1) would be (1’): ‘If it is absolutely certain that P is the case (if P has the probability 1), then it is necessary that P.’ Surely, premise (1) could not be analysed as (1’’) ‘If it is practically certain that P is the case (that is, if P has a probability near to 1), then P is necessary,’ since the mere probability, no matter how high, of P, being less than 1, would not warrant the necessity of P. Once we admit the change of premises (1) to (1’) and (2) to (2’), Kripke’s argument can be made completely explicit as saying:

1’  If it is absolutely certain that P, then it is necessary that P.
2’  It is practically certain that P.
3’  It is necessary that P.

Obviously, argument (B) is non-valid, since the modus ponens cannot be applied to (1’) and (2’) in order to give us (3’). The reason is that the antecedent of (1’) does not say precisely the same thing as (2’), which makes the argument equivocal, hence fallacious (absolutely certain is not the same as practically certain). We conclude that under more careful scrutiny Kripke’s argument is flawed, insufficient to convince us that the utterance ‘This lectern is not made of ice’ is a metaphysically necessary a posteriori truth.
   Now we can easily see the reason for Kripke’s misleading claim that the conclusion of his argument must be necessary a posteriori. He ignores the fine semantic differences made explicit by means of version (B) of his argument, and by doing so he jumps to a conclusion that unduly joins the necessity of his argument’s first premise with the aposteriority of its second premise, building what he calls a necessary a posteriori truth in the conclusion (3). Of course, we are still free to establish that it P is necessary in some weaker empirical sense of the word. In this case, we can say that P is as a necessary a priori assumption. In any way, the upshot is the same. Kripke is far from having given us reasons to believe in the explosive discovery that P is a necessary a posteriori truth.

Kripke then comes to the analysis of identities between proper names such as ‘Hesperus is Phosphorus’ and ‘Cicero is Tulli.’ These empirical identities are usually seen as contingent. However, for Kripke they are identities between rigid designators, which makes them necessary, since in the most diverse possible worlds these names will refer to the same object, which would not be possible if Hesperus weren’t Phosphorus or if Cicero weren’t Tulli. We could, he says, have identified Hesperus and Phosphorus with two different celestial bodies, but in this case the sentence ‘Hesperus is Phosphorus’ would have a different meaning. This would be the case, for example, if Martians had once inhabited the Earth and had identified Hesperus with Venus and Phosphorus with Mars... The same is true with the identity ‘Cicero is Tulli.’ According to him, it seems that this statement is contingent because sometimes we learn these names with the help of definite descriptions like ‘the greatest Roman orator,’ which are accidental designators, thinking that we identify the object through properties, when in fact such names are rigid designators.

In order to demonstrate that the statement ‘Hesperus is (the same as) Phosphorus’ cannot be necessary a posteriori, we can produce here an argument parallel to the argument applied by Kripke to the indexical case of the lectern made of wood. Calling Hesperus h and Phosphorus p we can construct the following Kripkean modus ponens:

     (h = p) → (h = p)
     h = p
     (h = p)

The conclusion of this argument is that ‘Hesperus is Phosphorus’ is a necessary identity that has been reached a posteriori.
   Nonetheless, also here the modus ponens does not apply because although the first premise is true, the second premise would only conjoin with the first one to reach the conclusion ‘(h = p)’ if it were able to give us an absolute assurance of the truth of ‘h = p.’ However, this is not the case. In order to get the absolute assurance that ‘h = p,’ which enables us to reach the conclusion of the conditional, this truth must be discovered, not by inevitably fallible human epistemic subjects only capable of practical certainty, but again only by God, the omniscient and infallible epistemic subject.[9]  Because of this, ‘h = p’ can here only be seen as an empirically achieved fallible conclusion, saying that it is practically certain (sufficienty probable) that ‘h = p,’ which is still far from absolute certainty. The following reformulation demonstrates the argument’s hidden flaw:

       If it is absolutely certain (with probability 1) that h = p,
       then (h = p).
       It is practically certain (with probability near to 1) that h = p.
       (h = p)

Since the absolute certainty required by the identity of the antecedent of the first premise with the second premise is not available, the equivocal character of the argument turns clear. We cannot use the modus ponens to derive the a posteriori necessity of h = p. The statement ‘Hesperus is Phosphorus’ is in this inter­pretation contingent a posteriori. It cannot be metaphysically necessary, because since this identity is only highly probable, it will always be possible that Hesperus is not Phosphorus. For instance: although extremely unlikely, it is logically possible that the gods have until now produced a great illusion of knowledge in human minds, and that the planets are nothing more than a swarm of fireflies that every night assemble to decorate the celestial Vault. In this case, Hesperus would have a different location than Phosphorus when seen by the naked eye, but it would look identical to Phosphorus when viewed through a telescope – not because it is the same planet or a planet at all, but as a result of an illusion.
   The second example given by Kripke is very different, and one should not confuse it with the last one. It concerns the utterance ‘Cicero is Tulli.’ Assuming the neo-descriptivist theory of proper names proposed in the appendix of chapter I, the localizing description for his identification is (concisely) ‘the person born in Greece on 3.1.106 BC and deceased in Rome on 7.12.43 BC,’ while the characterizing description is (concisely) ‘the most famous Roman orator, also a statesman, jurist and philosopher.’ His whole name was ‘Marcus Tullius Cicero.’ Since the proper name does not belong to the fundamental descriptions, but to the auxiliary ones (he could easily receive another name in a different possible world), Kripke is only relying on the fact that not all speakers know that Cicero and Tullius are parts of the same proper name as a convention in our actual world. The statement informs the reader that the bearer of the fundamental descriptions implied by each term flanking the identity sign is part of the whole name of the same person.
   The result is that the question turns out to be a trivial one, namely, to communicate to the hearer a convention regarding the auxiliary description ‘the person whose name was “Marcus Tullius Cicero”.’ Hence, the right answer is that ‘Cicero is Tullius’ is only the communication of part of a necessary a priori linguistic convention, since the convention that the whole name is ‘Marcus Tullius Cicero’ is something a priori, as much as the convention that a triangle is a trilateral figure. Moreover, to say that the statement ‘Cicero is Tullius’ is a posteriori would be to confuse its belonging to a definition in our actual world – which is a question of being informed about conventions – with the possible names that the same reference could have received in different counterfactual situations. Indeed, it is possible that Cicero could have received the name ‘Marcus Titus Cicero’ in a different possible world, making the identity ‘Cicero is Tullius’ false. However, this is as trivial as to say that in a very different language (or world) people use a different name for ‘triangle,’ for instance, ‘colmio.’[10] The statement found in a dictionary ‘triangle means colmio’ is not a necessary a posteriori statement. It is the obvious expression of a necessary a priori identity regarding conventions.

The next of Kripke’s examples concerns the identity between kinds of things, as in the already discussed statement Heat is molecular movement. Many think that this identity, being the result of empirical research, expresses an a posteriori truth. However, for Kripke this is a necessary a posteriori identity because the heat (in a gas) cannot be anything other than molecular kinetic energy, since the terms ‘heat’ and ‘molecular motion’ are rigid designators. It may be, he says, that the Earth could at some time be inhabited by beings who feel cold where we feel hot and vice versa, so that for them heat would not be identical with molecular motion. However, this would not be the case, since heat is understood as molecular motion as we feel it.

As noted in the Appendix to Chapter I, since we have ways to translate rigidity in descriptive terms for proper names, we have reasons to guess that the same can be done with general terms. That is, we could link the two ascription rules of heat in gas and kinetic molecular energy to create a unified ascription rule that has two different guises – two different but interchangeable main designative criteria, producing a necessary a priori identity.
   Since I have already said something about this, what I will do now is only employ the same strategy used above in order to discredit the thesis that we may have a case of a necessary a posteriori. Thus, considering heat in gas and molecular movement as rigid designators that necessarily designate the essence, we could build the following Kripkean argument calling heat in gas H and molecular motion M:

     (x) ((Hx = Mx) → (Hx = Mx))
     (x) (Hx = Mx)
     (x) (Hx = Mx)

Clearly, the same problem reappears. The first premise says only that if the identity (x) (Hx = Mx) is really the case, then it is necessarily the case that all heat is molecular motion, or, from an epistemic perspective, if it is absolutely certain that all heat in gas is molecular motion, then it is necessary that all heat in gas is molecular motion. However, since the identity affirmed in the second premise, being empirical, is inevitably fallible, the following paraphrase of the above argument would be inescapable:

    (x) If it is absolutely certain (with probability 1) that (Hx = Mx),
          then (Hx = Mx).
    (x) It is practically certain (with probability near to 1) that (Hx = Mx).
    (x) (Hx = Mx)

Here again the more explicit formulation shows an equivocal and consequently fallacious argument. Because the antecedent of the first premise isn’t the same as the second premise, we cannot apply the modus ponens and the conclusion does not follow. The conclusion is that we cannot in this way conclude that the statement ‘Heat (in gas) is the same as molecular movement’ is a necessary a posteriori truth. But if Kripke were right, this should be the case.

The last of Kripke’s examples should be the most important one. It is intended as a refutation of identity theories of the mind-body relation, according to which ‘Pain is (the same as) such and such a brain state’ would be a contingent a posteriori scientific discovery, yet to be made. But, as Kripke writes, ‘pain’ and ‘such and such a brain state’ are here rigid designators because they refer to essential properties. However, if this is the case, the identity theorist is in trouble, because this identity needs to be necessary, which clashes frontally with the fact that whenever you feel pain you do have pain, while no one is denying that it is possible to conceive that we have pain without having the corresponding brain states. For a theist philosopher like Kripke this makes identity theory implausible.
From my side, I find this argument puzzling. First, as a matter of fact, one can feel pain without being in pain, for instance, in the case of hypnotized people who feel inexistent pains. However, even if we ignore this, assuming that we cannot feel legitimate pain without having some qualitative state of pain this isn’t up to make a difference. Why does this force us to think that a future neuroscience might not be able to show us that by speaking of such and such a brain state we make a rigid reference to the same thing we experience as a state of pain, so that this identity would be necessary in terms similar to those of Kripke? It is true that feeling pain isn’t the same as detecting hotness outside by feeling hot inside. It is more direct. But in the same way as a Martian can feel cold when we feel hot, a Martian might feel a tingling sensation when we feel pain. And we can similarly imagine that feelings of pain, like those of heat, have other means of identification. Hence, the only real difference that remains between the two cases is that molecular movement in gas is found externally, outside a person’s head, while such and such a brain state is found internally, within a person’s head, what is not relevant for the point in question. Kripke concludes his argument by saying: ‘heat is picked out by the contingent property of being felt in a certain way; pain, on the other hand, is picked out by an essential property’ (1971, note 18). Why should this difference being consequential?
   In my view, in most cases Kripke confuses the a posteriori element of a contingent a posteriori discovery with the necessary element of an identity of the reference that belongs to a different interpretation of as identity, which makes it a necessary a priori truth. This leads him to believe in a mystical, metaphysical de re necessity, which is discovered a posteriori. In doing so, he assigns to ontologically unknowable identities the same status of epistemo­logically assumed identities. He proceeds as if we could assert ontological (metaphysical) truths without considering our epistemic capacities and their intrinsic fallibility. He refuses to accept that we can never completely separate the epistemic from the ontic; and in doing so, he denies an insight accepted by modern philosophers since Descartes, namely, that we lack access to trans-epistemic truths.

There is a considerable variety of arguments from Kripke and other externalist philosophers that deserve closer examination. In what follows, I will limit myself to some few comments, since a more detailed analysis would exceed the scope of this book.

1. There are a variety of supposed examples of necessary a posteriori truths that were later proposed by Kripke and others. Consider, for instance, the statement (i) ‘Cats are animals’ (Kripke 1980: 181-2). For Kripke this is a necessary statement, since we cannot conceive of a cat that is not an animal; but it is also a posteriori, since it was discovered a posteriori. For us it can receive a double interpretation, depending on the context. (a) Contingent a posteriori: a primitive tribe that sees a cat for the first time can easily conclude, based on its aspect and behaviour, that it is an animal like others. The tribe arrives at this knowledge a posteriori, since based on experience, and contingently, since it is liable to revision (it could well be that cats were forest gods taking the form of animals). (b) Necessary a priori: a zoologist, assuming the truth of our contemporary taxonomy, according to which the cat is classified as one organism belonging to the Animalia kingdom, would see statement (i) as necessary a priori. It is an a priori analytic statement, since (i) abbreviates the tautology (ii) ‘Animals called cats are animals.’ No sign of a necessary a posteriori.

2. Another form of necessary a posteriori later suggested by Kripke concerns origins. For him, rigidity makes true parenthood necessary. He considers the case of Queen Elisabeth II, daughter of duke and duchess of York (1980: 112 f.). Note, however, that this is already a biased example, since in the case of a queen the ovum origin acquires maximal importance, contaminating the characterizing description of its identifying rule.
   By contrast, consider the statement (i) ‘Ishmael Lowenstein is the son of Abel and Berta Lowenstein.’ According to a Kripkean philosopher, this statement should be necessary a posteriori because even if this is known a posteriori, an adult with different parents stemming from a different ovum and a different sperm cell would not be Ishmael Lowenstein.
   However, suppose that the adult Ishmael makes the shocking discovery that his parents are not his biological parents. There was a mix-up of babies in the hospital where he was born, and a subsequent DNA analysis showed that he was actually the son of Amanda and Mario Belinzoni, who was baptized with the name Carlos. Of course, this is no reason to think that Ishmael thereby ceases to be Ishmael. This name is even printed on his birth certificate and driver license. If asked, he could insist on answering that his name is Ishmael Lowenstein, probably with the agreement of others who know him. This is in consonance with our identification rule, since Ishmael still satisfies the localizing and characterizing conditions sufficiently and more than any other person.
   In any case, our conclusion may be less straight regarding the main point, namely, the whole statement (i) ‘Ishmael is the son of Abel and Berta Lowenstein,’ which concerns the question of parenthood.[11] One could use as a criterion of parenthood those who cared for the child and raised him lovingly until adulthood. In this case the statement ‘Ishmael is the son of Abel and Berta Lowenstein’ will be seen as true, even if he originated from a sperm cell from Mario and an ovum of Amanda. Under this understanding, the statement ‘Ishmael is the son of Abel and Berta Lowenstein’ is contingent a posteriori. Contingent because it could be false that they cared for and nurtured him; a posteriori because knowledge of this kind is acquired through experience.
   However, it is easy to imagine a situation in which Kripke’s view would apply. Suppose we were in Nazi Germany and the Lowenstein’s were Jewish. Suppose the Nazis had arrested the family. For the Nazis the criterion of parenthood was clearly biological. In this case, being the Nazis informed about the mix-up of babies, Ishmael Lowenstein would be considered the son of Mario and Amanda Belinzoni, while Carlos would be considered the son of Abel and Berta Lowenstein, being arrested and sent to a concentration camp. With regard to the proper name is less easy. However, it could even be possible that the Nazis had a rule according to which the true name of a person must be the name related to his biological origin, concluding that the true name of Ishmael Lowenstein is Mario Belinzoni and that Mario Belinzoni should be called Ishmael Lowenstein.
   Anyway, even in this case a statement like (ii) ‘Carlos Belinzoni (Ishmael Lowenstein) is the son of Mario and Amanda Belinzoni’ would not be a necessary a posteriori truth. In this case, parenthood and even naming turn out to be part of the characterizing description-rule. This could lead to a double interpretation of the statement. On the one hand, (a) It could be seen as a contingent a posteriori discovery, insofar as one emphasizes the fact that the name Carlos Belinzoni (= Ishmael Lowenstein) now means the same as the son of Mario and Amanda as an (a posteriori) discovered truth and a (contingent) practical certainty inductively achieved. On the other hand, (b) if one emphasizes a stipulated decision to treat ‘Carlos Belinzoni’ (= Ishmael) as an abbreviation of ‘the son of Mario and Amanda Belinzoni’ as essential part of his identification rule, we have an unifying identification rule and statement (ii) could be seen as necessary a priori.
   There is only one way in which the origin would be necessary a posteriori, namely, under the eyes of God. He knows that Ishmael is the son of Mario and Amanda Belinzoni, and he knows it as a de re metaphysical necessity. He knows because he is able to trans-epistemic knowledge. We, fallible knowers, do not possess this gift.

3. Worse than the necessary a posteriori is a later invention of Kripke called contingent a priori (Kripke 1980: 54-56). It is the case involving the platinum rod kept in Paris, which was once designated as the standard metric unit of length. According to him, analysis of meaning is something different from definition; the first is necessary, the second not (although he gives no justification for this). Then he claims that the definition of ‘one meter’ as ‘the length of S at to’ is not necessary a priori, but contingent a priori! The reason is that the term ‘one meter’ is a rigid designator while ‘the length of S at to,’ being a definite description, is an accidental designator, allowing the length to be possibly longer or shorter than a meter, for instance, due to heating or cooling. Thus, in a different possible world one meter could be a length different from ‘the length of S at to.’ Therefore, the statement ‘the Paris platinum rod is one meter long,’ although established a priori, is contingent.
   This argument could be strong enough if we accept the existence of some metaphysical reason for the distinction between names as rigid designators and descriptions as accidental designators. But the real reasons for the distinction are non-metaphysical, as I have made clear in the appendix of chapter I (sec. 7-8). From this perspective, Kripke’s affirmation that after being established definitions are neither meaning-giving nor necessary turns out to be highly questionable. For it seems clear that the definition of a meter as ‘the length of S at to’ is a stipulative definition made to establish the proper meaning of one meter. Thus, why cannot ‘one meter’ be established, as it seems, as a mere abbreviation of ‘the length of S during ∆t[12], whatever this length is, as it seems? Why cannot then ‘the length of S during ∆t’ be a rigid designator, no less than ‘the kinetic molecular energy’? Assuming this, our intuitive reasoning would be to think that if the length of the standard meter changes or not, the meter in its function as a standard of measure remains the same, since the standard meter is defined as whatever length S has in the ∆t in which it is used as a standard. This means that in any possible world where the standard meter exists, the length of this meter will continue to be the same, whatever this length is.
   Only for practical reasons it is better to use the most unchangeable possible standard meter, once we wish to preserve the comparative function of measuring length. For suppose that the standard meter were a kind of very elastic band, continually changing its length. It would remain the same standard meter, of course, but it would be utterly unpractical. Using this standard in accordance with the given definition, we could be forced to say that a woman who was 1.67 m tall two hours ago is 2.24 m tall right now; or objects with very different sizes could be the same size if they were measured at different times…
   The point is that if you accept that the statement ‘A meter is the length of S in ∆t, whatever length it has when measured’ presents the actual definition of a standard meter – and it really does – this definition isn’t contingent, but necessary, since it is a convention that cannot be falsified in any possible world where it holds. Moreover, this definition is a priori, for we do not need to make any experience to know its truth. Consequently, the following identity was the definition of a meter:

One meter (Df.) = the length of the standard rod S during any moment of ∆t, disregarding the possible world (the circumstance) in which its length is considered.

This identity is necessary and a priori; and its necessity is supplementary evidence that definite descriptions of stipulative definitions are rigid. They are rigid because we have established them as the definiens of a name, as in the present case.

4. Another attempt to exemplify the contingent a priori could come from Gareth Evans’ example with the name ‘Julius,’ which he artificially stipulates as ‘the inventor of the zipper’ (Evans 1982: 31). According to some, the statement (i) ‘Julius was the inventor of the zipper’ is contingent a priori. It is a priori because we do not need experience to know this; but it is also contingent, since it is possible that ‘Julius’ was dropped on his head when little and grew up too stupid to invent the zipper (Papineau 2012: 61).
   In my view, statement (i) has a double reading. On the one hand it is contingent a posteriori. It is contingent because in a counterfactual situation it could be that the zipper was not invented by anyone or that it would invented by several persons… but it is also a posteriori because its truth depends on experience to be learned of. On the other hand, assuming to be true that someone invented the zipper, we could paraphrase ‘Julius invented the zipper’ as (ii) ‘Under the assumption that someone invented the zipper, we decided to call this person “Julius”.’ However, this paraphrase of (i) is not contingent a priori, but necessary a priori. It is necessary because it is a harmless stipulation, and it is a priori because established independently of experience. In any case, we do not have the contingent a priori.

5. An amusing attempt is the following utterance: ‘I am here now’ by David Kaplan (1989: 509). Accordingly, this would also be a contingent a priori truth. It is a priori because, since each of its terms directly refers respectively to the agent, the place and the time of a given context of utterance, this excludes the possibility of its falsity. However, since we can imagine counterfactual circumstances in which I would not be here, this utterance is only contingently true.
   This example is also delusive. For ‘I am here now’ can also be false in the actual world! I remember a case related by Dr. Oliver Sacks of a patient who had a seriously deranged perception of temporal continuity. Because of this, her daily life was a succession of time-lapses: she could think ‘I am here now’ as if she were still in her bedroom, when in fact she was already in her kitchen. Thus, in this case, ‘I am here now’ is empirically false! This shows that the statement ‘I am here now’ is in fact contingent a posteriori, since it is falsifiable and dependent on the context of the experience to be learned about.

6. I also disagree with Hilary Putnam’s view, according to which the meaning of the word ‘water’ must be essentially external to our heads.[13] This is perhaps the most influential argument for semantic externalism. According to Putnam’s Twin-Earth fantasy, in 1750, Oscar-1 on the Earth and his Doppelgänger Oscar-2 on Twin-Earth – two nearly identical planets with the same history – were seeing that it was raining. Since in 1750 the chemical structure of water wasn’t yet discovered, all that Oscar1 and Oscar2 could have in their heads could be the same idea of a watery fluid (a fluid that at room temperature is transparent, odorless, tasteless…). However, without their knowledge, they were referring to very different compounds, Oscar1 to H2O, while Oscar2 to XYZ, since water on Twin-Earth (believe or not) has a very different chemical composition, summarized by Putnam as XYZ, even though having the same appearance and effects. For Putnam this proves that the meaning of water – which for him concerns essentially quantities of atoms with the same microstructure H2O – could not be in the heads of the Oscars, since in their heads they had the same state, namely, the idea of a watery fluid and nothing more. Putnam’s conclusion is the most famous statement of externalism: ‘Meaning just ain’t in the head.’(1975: 227) As he summarizes in a central passage:

Oscar-1 and Oscar-2 understood the term ‘water’ differently in 1750, although they had the same psychological state, and though, given the state of development of Science in their epoch, the scientific community would need to take circa 50 years to discover that they understood the term ‘water’ differently. Hence, the extension of the term ‘water’ (and, in fact, its meaning in the pre-analytic intuitive use of the term isn’t a function of the psychological state of the speaker) (my italics). (1975: 224)

This is a shocking conclusion, later radicalized by John McDowell’s inference that even the mind must be external to the head, because it is the locus of our manipulation of meanings (McDowell 1992: 36).
   My neo-descriptivist answer is that Putnam’s result comes from over­looking the fact that the word ‘water’ has two descriptive nuclei of meaning: a popular and a scientific one.[14] First, there is an old popular nucleus of meaning of the word ‘water.’ This nucleus is phenomenal or dispositional and can be summarized by the expression ‘watery fluid’. It is a fluid that at normal temperatures is transparent, odorless, quenches thirst, can be used to wash, is an universal solvent, extinguishes fire, falls from the sky as rain, forms rivers, lakes and oceans, turns into ice when cooled below 0 degrees C, turns into steam when heated above 100 degrees C, has high surface tension, etc. This was the usual meaning until the end of the eighth century. Then a new dimension of meaning was increasingly added: the scientific nucleus, which can be summarized as ‘quantities of H2O.’ It is the result from 2H2 + O2 = 2H2O, as can be shown by burning hydrogen mixed with oxygen, can be subjected to electrolysis, forms intermolecular hydrogen bonds responsible for its high surface tension, etc. Both nuclei of meaning are not just intrinsically inferential. They are also obviously descriptive (since in opposition to Putnam’s bias, the domain of what can be described is much wider than a merely perceptual domain, containing descriptions of dispositions, of micro-structures, etc.) and can be found today in any good dictionary.[15] We use the word ‘water’ in accordance with what we know from the inferential rules of these two nuclei on an everyday basis.[16] Furthermore, it is easy to see that in consonance with contextual variations, one of these clusters of meaning tends to come to the fore.
   This summary already allows a convincing internalist explanation of the Twin-Earth fantasy. First, in 1750 the two Oscars had only the nucleus of meaning expressed by ‘watery fluid’ in their heads, so that the extension and the meaning of the word water was the same for both of them. However, when Putnam considers what is happening, he is overvaluing and unconsciously projecting the scientific nucleus of meaning of the word ‘water’ in the utterances of the two Oscars, as if it were the only truly relevant one. What he does then is to treat the two Oscars as mere indexical devices for the projection of the new scientific nucleus of meaning, whose true locus is in fact our own heads (i.e., those of Putnam and his readers), since we know that Oscar-1 is pointing to H2O, while Oscar-2 is pointing to XYZ. Consequently, the different scientific meanings of the word ‘water’ are not in the world and outside of our heads, as Putnam believes. They are in Putnam’s head when he thinks his thought-experiment and in our heads when we read him, since today we all know some basic things about the scientific nucleus of meaning (H2O) and may guess that a different scientific nucleus with similar effects (XYZ) would maybe not be impossible. Finally, since Putnam and his readers have different scientific meaning-descriptions in their heads when unconsciously projecting them to Oscar-1 and Oscar-2 by using them as indexical devices, these different meanings remain, as they should, internal properties of minds. This also explains why we give them (by means of our instrumental referential devices called ‘Oscars’) different extensions.
   In a popular context of interest (e.g., of fishermen wishing to use water for cooking, drinking and washing) the sense that is emphasized in the statement ‘Water is H2O’ is that of a watery fluid. In this case, ‘Water is H2O’ means above all (b) ‘Watery fluid = fluid composed of H2O.’ This is, taken at face value, a contingent a posteriori statement. Contingent because, at least in principle (though very improbably), it could be proved false; a posteriori because it was learned from experience. Its modal form is ◊ (a = b) (added with a high level of probability).
   This neo-descriptivist view suggested above by the consideration that the meaning of ‘water’ varies with what we could call the context of interest in which a word is used, that is, the context of its circumstantial utility.
   In a scientific context of interest (e.g., in a chemist’s laboratory) the scientific nucleus of meaning is emphasized. Here ‘Water is H2O’ means above all (a) ‘Hydroxide of oxygen = H2O.’ Interesting enough, (a) is a necessary a priori statement with the modal form □ (a = b). In this context even if water were not a watery fluid, but something like a black oil, it could still be called water, insofar as it preserves the right microstructure.
   Conclusion: the Kripkean classification of the statement ‘Water is H2O’ as a necessary a posteriori statement results from a confusion between the a posteriori nature of statement (a) and the necessity of the similar statement (b). Since both senses are components of the whole meaning of ‘water’ and may alternatively come to the fore, it is easy to fall into a confusion resulting from lack of attention to the pragmatics of natural language, as Putnam and Kripke do overvaluing the scientific nucleus. We already spoke about these kinds of confusion when we examined Wittgenstein’s account of the transgression of the internal limits of language. In this case, the confusion is a matter of equivocity: the attempt to import the scientific into the popular use (cf. Ch. III, sec. 11).

7. There are two other examples of Putnam aiming to show that meaning is not only in the external physical world, but also in society. In the first one, he assumes that aluminum and molybdenum are only distinguishable by metalworkers and that Twin-Earth is rich in molybdenum, used to manufacture pots and pans. In addition, he imagines that the inhabitants of Twin-Earth call molybdenum ‘aluminum’ and aluminum ‘molybdenum.’ In this case, he writes, the word ‘aluminum’ said by Oscar-1 will have an extension different from that of the word ‘aluminum’ said by Oscar-2, so that they mean different things with the word. However, as they are not metalworkers, they have the same psychological states. Hence, the meaning of these words is external to what happens in their heads, depending on their societies.
   Our answer is the following. If we consider the words ‘aluminum’ and ‘molybdenum’ in the way they are used by Oscar-1 and Oscar-2, since they are not metalworkers, what they have in their minds is indeed the same. It is as much so as the extension that they can give to their concepts of aluminum and molybdenum, which in the example includes both. For the metalworkers of Earth and Twin-Earth, on the other hand, the aluminum of the Earth and the molybdenum of Twin-Earth (called by their inhabitants ‘aluminum’) have very different constituent properties, which means that metalworkers would have something very different in their heads. The Oscars may confuse both things, but only because they do not really know the intrinsic properties of these things, once they are using the words in a subsidiary sense. However, since we are informed about the differences between the amounts of these metals on both planets, we can consider the aluminum and the molybdenum respectively observed by Oscar-1 and Oscar-2 and without unawareness take both persons as referential devices for the different meanings that we have in our heads. In this case, we would say that Oscar-2 is pointing at what his linguistic community calls aluminum, but which is what we in our linguistic community call molybdenum, while Oscar-1 is indeed pointing to aluminum.
   That people should use the words in accordance with the conventions of their linguistic community does not make the meaning external. It only makes it dependent on the explicit or implicit agreement of members of their communities. In the case of the Oscars, this agreement concerns only superficial properties. In the case of metalworkers, this agreement also concerns intrinsic properties. These agreements are always in individual heads, even if differently distributed in a social network.
   In the second example, Putnam considers the difference between elms and beeches. Most of us do not know how to distinguish elms from beech trees. However, we are able to guess correctly that these words are not synonymous, having different extensions without our knowing their meanings. Hence, according to him the difference of meaning is not in our heads, but in society.
   In response to Putnam, the important point to be noticed is that most of us in fact do lack sufficient knowledge of the meaning of the words ‘elm’ and ‘beech.’ However, we already know something very generic about them: we surely know that they are trees, and we consider it very probable (though not certain) that these two names refer to distinct kinds of trees.[17] With the help of these convergent descriptions (cf. Appendix to Chapter I, sec. 4) we are able to insert these words into a sufficiently vague discourse. However, we do this often waiting for the distinguishing information to be given by specialists, those privileged speakers with sufficient knowledge of the meaning of these words. These are the persons really able to identify examples of these different kinds of trees, so that without them these words would have no use. The point is that the meaning – sufficient or not – is always in the heads of speakers, even if (I agree) this meaning is within the heads that build the network of a social linguistic community.[18]
   In these two cases, Putnam appeals to a division of linguistic labour in order to account for the diversity of dimensions of meaning that may be possessed by different speakers. As he writes:

We may summarize this discussion by pointing out that there are two sorts of tools in the world: there are tools like a hammer or a screwdriver, which can be used by one person; and there are tools like a steamship, which require the cooperative activity of a number of persons to use. Words have been though of too much on the model of the first sort of tool. (Putnam 1975, p. 229)

This is an important suggestion. However, this is not a suggestion that confirms an externalist conception of meaning. It is rather neutral. After all, the idea of a division of labour of the language was already suggested by internalist philosophers, from John Locke to C. S. Peirce (Smith 2005: 70-73), the former championing a theory of meaning as something built up of psychological ideas. In effect, the division of labour is perfectly compatible with the fact that, even if socially shared, the meaning remains in the heads of speakers, specialists or not, in different dimensions and degrees. In none of the cases above does the meaning need to be outside of heads.
   Finally, to be fair, Putnam expresses himself much more carefully in a later text (Putnam 1988, Ch. 2), e.g., by suggesting that ‘reference [as meaning] is fixed by the environment itself,’ calling it ‘the contribution of the environment’ (1988: 32). However, we can understand the word ‘fixed’ in two ways. In the first we understand ‘fixed’ in the sense in which the external physical and social world is what ultimately produces referential meanings in our minds-heads, which is an obvious truism – something that a weak internalist (= a very weak externalist) like myself would have no desire to deny. In the second way, what he means with that word ‘fixed’ remains a too subtle metaphor to find an intelligible rescue except by confessing that he is speaking trivially about reference.

8. Now, I wish to reinforce my anti-externalist arguments discussing Tyler Burge’s social externalism of thought, which is in some ways complementary to Putnam’s argument (Burge 1979). What Burge seems to have intended was, apart from Putnam, to show that not only is meaning outside the head, but also the proper content of thought or belief.
   I will first summarize Burge’s argument and then show that it is easy to find a much more plausible weak internalist explanation for what happens, simply by elaborating an objection already made by John Searle (2004: 284-6). In order to make it as clear as possible, instead of following Burge’s counterfactual mental experiment, I will follow Searle’s version. Suppose that a man called Oscar, residing in region A, feels pain in his thigh and goes to Dr. Black, saying:

(i) I think I have arthritis in my thigh.

Since arthritis is characterized as a painful inflammation of the joints, the doctor regards this belief as obviously false, since one cannot have arthritis in the thigh. Suppose now that Oscar travels to a very remote region B of his country and visits Doctor White for the same reason. But although in region A arthritis has its normal conventional meaning, in the remote region B people use the word ‘arthritis’ in a much broader sense, as referring to any kind of inflammation. Suppose that having forgotten his talk with the first doctor, Oscar complains once more to this new doctor that he has arthritis in his thigh, having in mind exactly the same. Now, in region B, as expected, the new doctor will confirm the suspicion, agreeing with Oscar’s unquestionably true belief.
   Based on such an example, Burge’s reasoning goes as follows. Without doubt, the psychological states of Oscar in the first and the second regions, when he claims he has arthritis in his thigh are exactly the same, as well as his behavior. But the thought-contents expressed in the two utterances must be different, since thoughts are truth-bearers and the thought expressed in the first utterance is false, while the thought expressed in the second is true, and the same thought cannot be both true and false! We can even mark the second meaning of the word ‘arthritis’ with a new word: ‘tharthritis.’ Burge’s conclusion is that the contents of the thoughts cannot be merely psychological.[19] These contents must also belong to the outside world, to the social communities to which the speakers belong.
   Against this conclusion, it is not difficult to find a commonsensical internalist-descriptivist explanation for what happens. For a healthy weak internalism (which admits that our mental subjectivity unavoidably depends on external inputs), in region B the concept-word ‘arthritis’ is the expression of an ascription rule constitutive of a meaning that is more general, designating any kind of inflammation. According to this rule, ‘an inflammation that occurs in the thigh’ serves as a criterial condition and belongs to the sense of the word in the linguistic community of region B, though not in the linguistic community of region A. Thus, although the thoughts expressed in the sentence ‘I think I have arthritis in my thigh’ said by Oscar in the two linguistic communities are exactly the same, there is a fundamental difference that was rightly recalled by John Searle in the following words:

Our use of language is presumed to conform to the other members of our community, otherwise we could not intend to communicate with them by using a common language. (Searle 2004, 184-5)

That is, when Oscar says to Doctor Black ‘I believe I have arthritis in my thigh,’ he must assume that his generalized ascription rule for the predicate ‘arthritis’ belongs to the language that other competent speakers of the language conventionally apply. The whole of what Oscar has in his mind (not only actually, but also dispositionally) in his utterance in the linguistic community of region A is:

(a)  I have arthritis in my thigh… [and I am assuming that pain and inflammation in my thigh are accepted as a usual symptom of arthritis by the linguistic community of region A, to which my present interlocutor, Dr. Black, belongs].

This is false, because the second sentence of the conjunction is false. Let’s now see what is (actually and dispositionally) meant when Oscar tells the second doctor that he has arthritis in his thigh:

(b) I have arthritis in my thigh… [and I am assuming that pain and inflammation in my thigh are accepted as an usual symptom of arthritis by the linguistic community of region B, to which my present interlocutor, Dr. White, belongs].

Now statement (b) is true. Although the statement ‘I have arthritis in my thigh’ says the same thing, it has a hidden indexical meaning that differs from (a) to (b). However, this hidden indexical content still belongs to Oscar’s mind. Thus, it is true that if we confine ourselves to the content expressed in Oscar’s thoughts in making the same utterance in both places, we see them as identical. However, the whole of what the hearers have in their minds (that is, in their heads) when hearing each utterance is different. It is different because Oscar wrongly assumes he is following the conventions accepted by doctor A from the first linguistic community, while he correctly assumes he is following the conventions accepted by doctor B from the different linguistic community.
   This assumption that the verifiability rules constituting the content of thoughts should be in accordance with the conventions of the linguistic community in which it is expressed in order to achieve truth is infringed on by Oscar when he speaks with the doctor from community A. But the correlative assumption isn’t infringed on in community B, when Oscar speaks with Doctor White. The conventional truth-makers given to the members of the two social communities of speakers are different, thought the indexical assumptions to be related to them are the same.
   To be fair to Burge, we need to notice that he has called attention to something important: the truth or falsehood of the utterances depends on their conformity with linguistic conventions adopted by the speaker’s community. This is already a relevant point, although it does not reach the claim that anything involved in thought-content or belief is outside the internal psychological realm, in some way dispersed across the external social-physical environment, as a strong externalist would like to believe.
   Finally, the given explanation allows us to make a healthy internalist paraphrase of the well-known distinction between narrow content and wide content. For the externalist point of view, the narrow content is one that is in the speaker’s mind, while the wide content is in some way external. The healthy internalist analysis of Burge’s example allows us to propose that the narrow content of a thought is the semantic-cognitive verifiability rule that constitutes it. This rule is expressed by the statement ‘I think I have arthritis in my thigh.’ On the other hand, the wide content of a thought is what is assumed in the speaker’s mind as the social convention that he expects to be satisfied by the narrow content.

8. Finally, one word about John Perry’s argument for the essential indexical (1979). I will be brief, since I am repeating an argument presented in detail in another text (Costa, 2014, Ch. 4). Against Frege, Perry’s view is that the senses of indexicals are inevitably tied with the external circumstances of utterance, which can be proved by the fact that one cannot translate them into eternal sentences without loss. The upshot is that, regarding indexicals, externalism of meaning is unavoidable.
   In Perry’s main example, he is in a supermarket and discovers that there is a trail of sugar on the floor. He begins to search for the source of the mess only to discover that he himself is the one who is spilling sugar on the floor, and this leads him to say: (i) ‘I am making a mess,’ immediately changing his behavior. Now, suppose that we translate his statement into a non-indexical statement like (ii) ‘Perry is making a mess.’ This (nearly) non-indexical statement cannot preserve exactly the same meaning. He could, for instance, be suffering from Alzheimer’s disease and has forgotten that his name is Perry. In this case he would know the truth of (i), but not the truth of (ii).
   However, I think there is in fact a way to preserve the sense of the indexical, detaching it from its context. It is a technique that I call transplantation: if you need to change the location of a plant, you usually don’t take the plant alone, but the plant together with the earth in which it is rooted, often also together with a plastic cover involving the earth. Applying an analogous technique, here is how Perry’s example appears after transplantation:

(iii) At 10:23 a.m. on March 26, 1968 in the confectionary supplies section of Fleuty Supermarket in the city of Berkeley, CA, after noticing a sugar trail leading away from his shopping cart, Perry says that he is making a mess (or: ‘I am making a mess’).

What counts here is the truth of the eternal sentence[20] (iii) in which the indexical subordinate sentence is presented after a that-clause. Although containing indexicals (‘he’ plus present tense), statement (iii) in no way refers to the indexical context, since the indexical subordinate sentence refers indirectly. It refers to what Frege called the thought (the belief-content) expressed by the subordinate sentence that follows the that-clause. Thus, protected by its surrounding description (the ‘volume of earth’ offered by the eternal sentence) the sense of ‘I am making a mess’ is here integrally transplanted without loss into the non-indexical context of a referring thought-content.[21] What this argument shows is that the so-called essential indexical is not essential, since we can internalize its apparently external components.

[1]  Rejecting the view of a particular as a bundle of abstract properties, he concludes: ‘What I do deny is that a particular is nothing but a “bundle of qualities”, whatever that may mean’ (1980: 52). He was certainly unaware of the in that time recently born trope theory.
[2] The right expression would be ‘With practical certainty (a = b).’ But the modal language is too poor to express a possibility made of a high probability that gives us practical certainty.
[3] It seems that the real reason why we distinguish regularities that are natural laws from those that are merely coincidental is that the former are not only strongly inductively grounded, but also well-entrenched, that is, strongly inferentially integrated with our most plausible scientific system of beliefs. This creates the illusion that our knowledge of natural laws is of something that exists by logical necessity.
[4] D. M. Armstrong defended the view that the scientific laws are necessary because they are relations between universals, what explain their resistance to counterfactual situations. However, the price that must be pay seems to be too high (1983).
[5] In my view this point was already touched by Allan Sidelle, as he insisted that the so-called necessary a posteriori could be seen as the analytical result of convention (1989: Ch. 2, 4).
[6] The concept is important since when we say that our (empirical) knowledge is justified true belief, what we have regarding the condition of truth is practical certainty. Thus, empirical knowledge is based on practical certainty (cf. Costa 2014, Ch. 5).
[7] As Popper clearly saw, even if we finally reach the absolute truth we would not be able to recognize it as the absolute truth, we would not be able to have absolute certainty. Notwithstanding, there are further questions, like the supposed exception of the Cartesian cogito (‘I think, I exist’) and the question about the extension of our empirical knowledge, which I cannot address here.
[8] Hilary Putnam’s objection against the sceptical possibility that one can be a brain in a vat, hallucinating an unreal virtual reality produced by a supercomputer on the planet Omega is controversial, to say the least (1981, Ch. 1). According to Putnam’s externalist point of view, if I am a brain in a vat, in order to have thoughts like those of brain, vat, water, etc., I need to be in causal contact with these things; hence, once I have these thoughts, I cannot be a brain in a vat. The problem with Putnam’s argument is that it ignores the flexibility of language. There is no reason to believe that electrical patterns in the brain cannot misleadingly appear to us as brains, vats, water, etc., being falsely represented and intended as such, insofar as we admit that outside factors (like the supercomputer on the planet Omega or any really external world) could systematically produce these patterns.
[9] It seems that God would be the only being able to know created things in their metaphysical necessities de re, since he knows them by sustaining them in their existence.
[10] ‘Colmio’ means triangle in Finnish.
[11] Today there are several competing theories of parenthood (genetic, labor-based, intentional, causal and pluralistic ones), and there is no consensus on the right cluster of criteria (cf. Brake & Millum 2016, sec. 4).
[12] The symbol ‘∆t’ is more correct than ‘to’ because the rod serves as a standard not only at to but during all the time in which it was conventionally designated to hold its function.
[13] I say ‘essentially’ because Putnam admits that surface descriptions (stereotypes) and classifications (semantic markers) are internal secondary mental features of meaning (1975: 269).
[14] For a more detailed argument, including a more careful neo-descriptivist analysis of the meanings of the word ‘water’, see Costa 2014b.
[15] For instance, the main definition in a Merriam Webster dictionary contains elements of both, popular and scientific nuclei of meaning. It is the following: ‘water = the liquid that descends from the clouds as rain, forms streams, lakes, and seas, and is a major constituent of all living matter and that when pure is an odorless, tasteless, very slightly compressible liquid oxide of hydrogen H2O which appears bluish in thick layers, freezes at 0°C and boils at 100°C, has a maximum density at 4°C and a high specific heat, is feebly ionized to hydrogen and hydroxyl ions, and is a poor conductor of electricity and a good solvent.’ (The descriptive relevance of the dispositional and scientific properties of water and its presence in dictionaries was first noticed by Avrum Stroll, 1996: 71).
[16] We need to know only the most common descriptions and enough to use the word adequately in more or less vague contexts; we do not need to know all descriptions; even chemists do not know all of them. Did you know, for instance, that when water is cooled to near absolute zero (-273.15° C.), it again turns into a liquid?
[17] In his (1988: 29) Putnam notices that if I know that a beech isn’t an elm I also know that an elm isn’t a beach, what means that my knowledge is symmetrical, so that the representations are the same; moreover, the words ‘beech’ and ‘elm’ are only phonetic shapes without meaning (1988: 27). But the point is that we know that by these two names we mean different kinds of trees and the description ‘beech is a tree different from an elm tree’ is sufficient to allows me to insert these words in the discourse as referring to different kinds of trees.
[18] We can also find the right information in books, in the internet, etc. but in order to be there it must first be in some way or measure in human minds.
[19] He wrote this in a more convoluted way: ‘The upshot of these reflections is that the patient’s mental contents differ while his entire physical and non-intentional mental histories, considered in isolation from their social context, remain the same.’ (Burge 1976: 106, my italics)

[20] This is not a perfect eternal sentence, but it is questionable if a statement without any indexical involvement is possible. If I say, The Earth is round I am already localizing the object in the solar system.
[21] Phenomenal elements are obviously lost, but they do not belong to the conventional meaning. For a reconstruction of Frege’s indirect reference, see the Appendix of Chapter IV, sec. 5 (iv).