Can a Case for Naturalism be Naturalized-R.K. Garcia 1 CAN A CASE FOR NATURALISM BE NATURALIZED? ROBERT K. GARCIA Texas A&M University robertkgarcia@gmail.com www.robertkgarcia.com Penultimate draft. Final version to appear in Aporía: Revista Internacional de Investigaciones Filosóficas According to Barry Stroud, the controversy over naturalism ultimately concerns deep disagreements over what counts as "natural". However, he points out, "those disagreements are not themselves to be settled by what can be recognized as straightforwardly 'naturalistic' means. So the one thing that seems not to have been 'naturalized' is naturalism itself." (1996, 43). Taking Stroud's suggestion, I will argue that justifying belief in naturalism requires the epistemic resources which naturalism repudiates, viz. that a case for naturalism cannot be itself naturalized. The paper is structured as follows. In Section (I) I will exhibit the central features of a version of naturalism. In Section (II) I sketch a general case for naturalism. In Section (III) I consider the justification of belief in naturalism on an externalist conception of justification. And in Section (IV) I consider two characteristics of the case that resist "naturalization." I. The Central Features of Naturalism David Papineau suggests that for the naturalist "all philosophical theorizing" is for the task of bringing "coherence and order to the total set of assumptions we use to explain the empirical world" (1993, 1--‐3). Furthermore, "there is no reason to place even first philosophy outside science" (1993, 43). 2 Laurence BonJour has suggested that this subjugation of the a priori is motivated by a general premise, namely, that rationalism is "incompatible with allegedly well--‐established theses [e.g., naturalism] about the nature and limitations of human beings and human intellectual processes" (1998, 153). Thus, the naturalist eschewal of genuine1 a priori justification and knowledge raises an important question. Can a case for naturalism be denuded of a priori concepts and yet remain coherent and plausible? Here I will take naturalists to be committed to the following set of propositions (N): a) All facts are physical facts, capable of third--‐person definite description. b) Empirical knowledge is knowledge simpliciter. c) All modes of knowledge are empirical or reducible to empirical modes. d) There is no genuine a priori justification or knowledge. Concerning (d), the naturalist claims that all cases of apparent a priori truth can be either reduced to "safe" analytic truths or eliminated altogether. In the former case, a priori truths are reduced to analytical truths that are constituents of contingent linguistic conventions. In either case, genuine a priori truths are considered unnecessary to account for our knowledge about the world. I have excluded an externalist approach to epistemology from my characterization of naturalism in order to consider both externalist and internalist approaches to establishing a case for naturalism. It is important to note that the commitments of naturalism establish the parameters within which the naturalist case must be made. Thus, for example, a case for naturalism cannot employ genuine a priori justification or knowledge. II. A General Case for Naturalism It is doubtful that there is a specific case for naturalism that would be accepted by all naturalists. Fortunately, here it will suffice to utilize a standard form of argument, modus ponens, where P represents the set of premises and N 1 As discussed below, "genuine" a priori justification or knowledge cannot be eliminated or reduced to "mere" analyticity. 3 represents the set of naturalistic tenets constituting the conclusion. Thus, we may sketch a general case for naturalism (NC): (1) If P, then N. (2) P (3) Therefore N. Of course, an argument for naturalism need not deploy modus tollens. However, since the failure of any one argument for naturalism would not constitute a refutation of naturalism, NC, as a general sketch, is intended to encompass any argument for naturalism (since it seems that an argument in any other logical form could be translated into modus ponens). Hence, if NC fails, there can be no successful argument for naturalism. In addition, the use of modus ponens allows for some general observations that would seem true of any valid argument. Such observations will illuminate essential characteristics of NC that seem to be a priori in character, and thus must be naturalizable for NC to avoid self--‐ refutation. III. Externalist Justification and Belief in Naturalism The challenge the naturalist faces is justifying every requisite aspect of NC. Obviously, for NC to be valid, the premises must entail or probabilistically imply the conclusion. Not so obvious, however, is the challenge for the naturalist to justify that entailment, viz. the principle of modus ponens that the premises exemplify and presuppose. Furthermore, for NC to be sound, its premises must be justified-whether the premises are deductive or inductive claims. Thus, since justification is so important, it will be necessary to consider rival conceptions of justification advanced by externalists and internalists vis--‐à--‐vis a case for naturalism. While my discussion must be brief, I hope to suggest that (i) that on an externalist conception of justification, a person could never justifiably believe that she actually is justified in believing naturalism to be true; (ii) that an externalist conception of justification is "unnatural," either being itself an a priori concept, or presupposing a priori concepts; and (iii) that, as an implication of (i) and (ii), an (at least partially) internalist conception of justification is necessary to make a case for a 4 justified belief in naturalism-assuming that such a case can otherwise be made. On the basis of an externalist account, according to which a belief is justified in virtue of there being a suitable causal connection between the belief and the external state of affairs that the belief is about, it would seem impossible to ever show that belief in naturalism is actually justified. A reliabilist, for example, will argue that belief in naturalism is justified if a reliable process produces it. Of course, since it is possible for one's belief in naturalism to be reliably or unreliably produced, the relevant question for an externalist is whether one's belief in naturalism is reliably produced. To this, the reliabilist could answer that if a reliable process produces one's belief that one's belief in naturalism is reliably produced, then one would be justified in believing that one's belief in naturalism was justified. However, as Richard Fumerton has argued, this is either circular or viciously regressive (1995, 175--‐177). Alternatively, an externalist could answer by describing the nomological factors that generated one's belief in naturalism and giving reasons to think that such a process is appropriately reliable. Unfortunately, the same question must be asked of such an account: "How is belief in this account justified?" However, an externalist qua externalist cannot answer, "Because it seems that this account constitutes a good reason to believe that the belief in naturalism was reliably produced," for such phenomenology cannot, on an externalist account, contribute to justification. Thus, it seems that an externalist is not able to establish actual-rather than merely possible-justification for belief in naturalism. Although a person might be justified in believing naturalism to be true, a person could never justifiably believe that she actually was justified in believing naturalism to be true. Another problem for the naturalist with regard to externalism concerns its conditional conception of justification. The conditional "If a belief's etiology is reliable, then the belief is justified" is an a priori claim that in no way seems analytically true. Even if the conditional was taken to indicate a probabilistic entailment, attempting to justify the conditional on empirical grounds not only leads to the regress indicated above, but also seems to require the justification of certain a priori principles such as the principle of credulity. Thus, externalism seems to require genuine a priori 5 justification. This however, makes externalists and naturalists ill--‐suited allies. On account of the difficulty of establishing NC on an externalist conception of justification, I will proceed by evaluating NC on a conception of justification that includes some internalist conditions, such as that justification may be a function of states cognitively accessible to the believer. IV. Aspects of NC Which Resist Naturalization I will now consider two "unnatural" aspects of NC. The first concerns the justificatory status of NC's premises. BonJour argues that the premises of an argument attacking genuine a priori knowledge must, at pain of self--‐defeat, be a posteriori in character. Yet, he argues, it is not clear how premises known a posteriori can have any substantial contribution to an argument against the a priori. While unapologetical about this seemingly simple line of argument against those who would attack the a priori, BonJour does consider it decisive (1998, 155). I aim to show just how decisive it is. The first premise is a conditional: if P were to obtain, then N would obtain. What is interesting about conditionals is that they are claimed prior to the fact. It is the entailment relation between them-P entails N-that is claimed, apparently, a priori. The question is whether NC would succeed if this entailment was reduced to an analytic truth or eliminated altogether. Whether this entailment is understood probabilistically (i.e., P probably entails N) matters not, since the claim would still be a priori. Since the entailment is necessary for a case to succeed, the naturalist cannot just eliminate the entailment relation. Rather, she must be able to reduce the entailment relation inherent in (1) to an analytic truth. The prospects for such a reduction seem slim. An example of a reducible entailment relation is the following: For any person X at time t, if X is a bachelor, then X is an unmarried male. This is analytically true in virtue of the fact that, by definition, all bachelors are unmarried males. That (1) will not survive such a reduction can be shown by considering the type of content it must have. At pain of contradicting the conclusion of NC (i.e., that there are no non--‐empirical facts), P must represent a set of premises each of which is a wholly empirical observation. However, by dint 6 of the fact that empirical claims are, at their highest possible generality, inductive inferences, empirical claims can never, by themselves, justify universal assertions. As the bachelor example shows, entailment relations may be reduced to analytical truths when there is a presupposed universal assertion (e.g., all bachelors are unmarried males). To reduce (1) to an analytic truth, however, the naturalist will not be able to presuppose the universal claim that "all Ps entail N" without begging the question. Nor can the naturalist establish this universal assertion on the basis on empirical observations, since, obviously, it will never be possible for her to observe that every P entails N. Hence, it seems that the entailment relation inherent in (1), if true, is an a priori claim. This evinces a problem for the second premise (2). If the premises in P must be empirical claims, and empirical claims are justified via inference from empirical observations, then the naturalist must be able to justify such an inference (BonJour 1998, 155). The justification of principles of inference, however, would seem an impossible task for the empiricist qua empiricist. Hence, it seems that the only available justification for inductive inferences is a priori justification. A second aspect of NC to consider is its form. The argument must be of a valid form for it to be sound. Thus, implicit in the argument is the "premise" that modus ponens is a justified logical inference. This premise, then, must itself be justified naturally. For the naturalist, the fact that the validity of modus ponens seems intuitively (i.e., non--‐ empirically) obvious in no way satisfies its need for justification. Indeed, part of what must be accounted for is the way in which and the fact that the validity of modus ponens seems intuitively indubitable. It is difficult, however, to see how the "observation" that modus ponens is a valid inference could be an empirical observation. From merely reading the set of written propositions which represent NC, one does not thereby "read" that modus ponens is a valid argument form. Moreover, it would not help to offer an argument for the validity of modus tollens, since such an argument would itself assume the validity of some form of inference. Thus, it seems that the validity of modus tollens is a primitive fact apprehended by the mind in an intuitive, non--‐empirical manner. The naturalist, however, has the option of construing modus tollens as an analytical truth, one true by definition. 7 Here, justification results from understanding the meaning of a proposition. BonJour, however, argues that there is no significant difference between the Fregean "definitional" conception of analyticity and the a priori concept of justification: in both accounts one derives justification from understanding or grasping the meaning of a proposition. Thus, what the Fregean conception fails to account for is how we are justified in believing propositions which are true by definition. For example, the fact that the intensional meaning of the word "humans" includes the intensional meaning of the word "men" does not explain how we justifiably know or believe that the proposition "All men are humans" is true. What seems clear is that this mode of knowledge is not an empirical one. Furthermore, the observation that certain premises exemplify the modus ponens form is not an empirical observation. Consider an example. Let the following propositions represent a series of thoughts had by Foghorn Leghorn: (4) I dropped an egg on the floor. (5) All eggs dropped on the floor break. (6) Therefore, the egg broke. For the sake of argument, grant that both premises are wholly justified on the basis of Foghorn's empirical observations, and that he did not in any way empirically verify the conclusion. Further, assume Foghorn has studied logic. After having the series of thoughts, Foghorn can reflect and thereby know (7) that his conclusion (6) is justified, and (8) that his series of thoughts exemplify a valid form of inference, namely, modus ponens. Obviously, none of the empirical facts he observed entail (8). (As argued above, none of them would entail (7) either, since (5) could not be established by empirical facts-but I have granted (5) for the sake of argument). Thus, while the knowing that (8) is not necessary for justifiably believing (6) or (7), it is a distinct item of knowledge occasioned by empirical facts but not accounted for by them. Thus, since no amount of empirical observations will constitute the observation that a series of thoughts or propositions 8 exemplify modus ponens, such an observation is not an empirical observation. With regard to NC, for one to justifiably believe NC to be valid, one must "see" NC to exemplify a valid form of inference. However, since this kind observation cannot be empirical, the validity for NC cannot derive from empirical facts (though, of course, it may be occasioned by them). Thus, to justifiably believe the form of NC to be valid, the conclusion of NC would have to be false, since there must be both a non--‐empirical mode of knowledge and non--‐empirical facts therewith known. Of course, the validity of logical inferences such as modus ponens is not just "seen" to be merely true, but necessarily true. We cannot conceive of any possible world where the proposition "If all A's are F, then some A's are F" would be false. The naturalist may respond in two ways to possible--‐world talk. On one hand, the naturalist may claim that necessity is identical with facts about possible worlds. According to Robinson, however, this "achieves nothing if our knowledge of possible worlds rests entirely on a priori intuitions about modality" (1993, 10). On the other hand, the naturalist might object that possible--‐world talk is an a priori enterprise, and thus is question begging-but this rather drastic reply would seem to be a reductio of the position. Nevertheless, even if we constrained our imagination to this world, it is still inconceivable that at any time or place the proposition "If all A's are F, then some A's are F" could be false. Thus, the modal status of a priori truths escapes a naturalist account. Thus, we have three options: (a) There is no justification for taking (3) to follow from (1) and (2). (b) The justification for taking (3) to follow from (1) and (2) can never be established, since it requires an infinite regress of "contingently valid" inferences. (c) The justification for believing (3) to follow from (1) and (2) is derived from an a priori insight (say) into the inconceivability of the contrary. Since (a) and (b) fail to justify the validity of (3), and (c) justifies the validity of (3) at the cost of employing genuine a priori justification, it seems that there can be no "natural" justification for the validity of (3). 9 Some philosophers, however, attempt to deny the apparent necessary character of an a priori proposition by identifying the "necessity" with a contingent linguistic convention. If a priori truths are "true by definition," and definitions are contingent linguistic conventions, then a priori truths are "made true" contingently by us, viz. through our contingent assignment of intension to a word. However, even if a priori truths are true merely by definition, this fails to account for the fact that the form of a proposition is presupposed by and independent of its expression in a language. If the above observations are correct, any case for naturalism will require for its success the very epistemic resources which naturalism disallows. Hence, a case for naturalism seems to defy naturalization. WORKS CITED BonJour, L. (1998). In Defense of Pure Reason, Cambridge: Cambridge University Press. Fumerton, R. (1995). Metaepistemology and Skepticism, Lanham, Maryland: Rowman and Littlefeild Publishers. Papineau, D. (1993). Philosophical Naturalism, Oxford: Blackwell. Robinson, H. (1993). "Introduction", in Objections to Physicalism, ed. H. Robinson, Oxford: Clarendon Press. Stroud, B. (1996). "The Charm of Naturalism," Proceedings and Addresses of the American Philosophical Association, 70 (2).