Metaphysics of natural species (6)

Abstract

The sixth lesson continued along this path, and turned to more contemporary philosophical history, by examining the semantics of ENs proposed in the mid-1970s by Saul Kripke [1] and Hilary Putnam [2]. These two authors, albeit in different ways, believe that a semantics of NE terms is possible, which is capable of determining a class of general terms that do indeed designate NEs, in the metaphysical sense of the term: chemical elements are such species, whoseessence can be discovered empirically, and which are metaphysically necessary even though they can be known a posteriori. There are therefore theoretical identities such as "water is_H2O" or "gold is the element whose atomic number is 79", and the semantics of the terms will enable us to distinguish between these authentic EN terms ("gold" or "water") and unnatural ones ("bachelor" or "pencil"). We have therefore analyzed this desire to align the semantic perspective with the metaphysical perspective in both the Kripkean and Putnamian currents. Putnam's focus is on relativism in the philosophy of science (Kuhn and his paradigms [3]); Kripke's focus is more on the supposedly necessarily a posteriori status of "theoretical identifications": these general terms that are EN terms are analogous to a semantically distinctive category of singular terms, namely, proper nouns. The ambition is thus to give new prominence to essentialism (hitherto associated, more than with the Aristotelian notion, with the dubious epistemology of Cartesian intellectualist rationalism), an essentialism that removes all mystery from essences, which are no longer said to be known a priori by means of a rational faculty. If it is empirical investigation that gives us knowledge, we are no longer in the presence of unintelligible entities.

The analysis therefore focused first on the Kripkean approach, breaking down its stages: critique of the Frégeo-Russellian conception of names through three arguments (modal, epistemological, semantic); solution (inspired by Stuart Mill) to remedy the difficulties of the descriptivist conception: proper names are non-descriptive, they refer directly. A "name-acquisition transaction" takes place, in the course of which an object, x, is chosen by a speaker in an "initial baptism" (Kripke, 1980, 97; transl. p 84 ff.). What determines the referent is the actual chain of communication, not the criteria for identifying the referent implicitly accepted by the speaker or the language community. Proper nouns are "rigid designators", referring to the same object in all possible worlds; we can thus ask counterfactual questions about it without worrying about whether or not we can identify it in a possible world: "Although the man (Nixon) might not have been president, he could not not have been Nixon (even if he might not have been called "Nixon"), and it is because we can rigidly refer to Nixon, and stipulate that we are indeed talking about what might have happened to him (under certain circumstances), that trans-theoretical identifications are not, in such cases, problematic [4]." Individuals may indeed change their names (Erich Weiss becoming Harry Houdini): but each independent baptism is the source of its own causal chain of reference-preserving links. What emerges from these analyses is an important distinction between two types of necessity: metaphysical and epistemic. The identity statement "Harry Houdini is Ehrich Weiss" is metaphysically necessary given (1) the necessity of identity, (2) the rigidity of proper names, and (3) the truth of the identity statement. But the identity statement is not epistemically necessary, since its truth does not follow simply from reflection on the names "Harry Houdini" and "Ehrich Weiss". There is therefore a strict difference between the identity statement "Ehrich Weiss is Harry Houdini" and "a bachelor is an unmarried man". Although both are metaphysically necessary, only the latter is epistemically necessary: its truth necessarily follows from reflection on the meaning of the terms "bachelor" and "unmarried man", and as such, it is knowable a priori. The former, by contrast, has no epistemic necessity, and is therefore knowable onlya posteriori. Kripke then extends the analysis of proper nouns to EN terms (ibid., pp. 104-108). He shows that, in the case of terms of mass ("gold", "water", "iron pyrite"), we are perfectly capable of identifying the actual referent of gold or false gold: it's not the meaning that changes, we've simply moved on to another substance, another thing. Applied to species such as "tiger", "cat", the analysis shows that "whether a given species is a species of animal is a question that can only be decided by empirical examination".

The review continued by introducing Putnam's arguments, which, although following distinct paths, are close to those of Kripke, and showed the crucial role played by the causal theory of reference (vol. 2 of Philosophical Papers). Putnam begins by replacing the problem of signification (whose logicalpositivist approach he criticizes) with that of reference (pp. ix-x), and then considers what might "fix" the latter. The "new theory of reference" establishes that the reference of theoretical terms and EN terms is generally fixed by a network of laws, not by analytical definition. The use of a word like "water" or "gold" depends "on our possession of paradigms," which we have agreed to recognize as models of the species. What makes something gold is that it is of the same nature as the paradigms or, in current physical theory, that it has the same composition, since "it is the atomic composition that determines the nomological behavior of a substance"(Philosophical Papers, vol. 3, 73). A lemon is what it is because it has the same nature (the same DNA) as paradigm lemons, not because it obeys a series of criteria (yellow color, thick skin, tart taste...) laid down in advance. As in the Kripkean theory of proper nouns, then, it is things given existentially and not by criteria - the actual things that have played a causal role in our acquisition and use of the term - that help to fix the reference. A term refers to something if it is in the right relation to that thing (causal continuity for proper names: the person or thing originally "baptized" with the name; identity of "nature" for species terms). It's the evolution of our theories on the nature of persons and species, and not a priori criteria , that allows us to indicate the right causal continuity, what it means to "share a nature". So, once we've discovered that water is _H20, we can no longer call substances with different chemical compositions "water", even if they superficially resemble water. The nature of something can therefore determine the reference of a term, even before that nature is discovered. But, by the same token, no set of operational criteria can totally fix the meaning of the word "gold", for as we develop better theories of gold's constitution and more elaborate tests of substances' behavior, we can always discover flaws in previous tests. By denying that proper names and EN terms are synonymous with definite descriptions or reduce themselves to conjunctions of criteria, the theory thus in a sense rehabilitates the idea that things and species have "essences", or at any rate natures: that they must have certain characteristics in order to be the things (or the kind of things they are). But at the same time, in Putnam, as in Kripke, it "liberates" this notion from its links with a priorist epistemology(Philosophical Papers, vol. 3, 74).

References

[1] Kripke S., Naming and Necessity. Oxford: Basil Blackwell, 1980 (First published in Harman G. and Davidson D. (eds.), Semantics of Natural Language, Dordrecht, Netherlands, D. Reidel, 1972.); French translation, by F. Récanati and P. Jacob, La logique des noms propres, Paris, Minuit, 1984.

[2] Putnam H., "The meaning of 'meaning'", in Gunderson K. (ed.), Language, Mind and Knowledge: Minnesota Studies in the Philosophy of Science, VII, Minneapolis: University of Minnesota Press. 1975. Republished in Putnam H., Mind, Language and Reality: Philosophical Papers, vol. II, Cambridge, Cambridge University Press, 215-71. Also in Putnam H., Representation and Reality, Cambridge, Mass., MIT Press, 1988; trans. fr. by C.Tiercelin, Représentation et réalité, Paris, Gallimard, 1990; and Putnam H., Realism with a Human Face (edited by J. Conant), Cambridge, Mass., Harvard University Press; trans. fr. by C. Tiercelin, Le réalisme à visage humain, Paris, Gallimard, 1991.

[3] Kuhn T.S., The Structure of Scientific Revolutions (^3rd ed.), Chicago, Chicago University Press, 1996 (First edition 1962).

[4] Kipke S., La logique des noms propres, op. cit.