Behavior and Philosophy, 44, 46-79 (2016). ©2016 Cambridge Center for Behavioral Studies MENTALISM VERSUS DUALISM: REPLIES TO COMMENTARIES José E. Burgos1 University of Guadalajara ABSTRACT: The target paper’s main point is that mentalism and, to this extent, mentalistic (e.g., cognitive) psychology can only be materialistic and, hence, cannot be dualistic. The commentaries to the paper are insightful and stimulating. A few call for corrections, the rest for further clarification. Most criticize the mind-brain identity theory. This criticism is beside the point, as I did not intend to champion this theory (or functionalism), but only use it to illustrate how mentalism commits us to materialism. Still, all the criticisms of the theory are fallacious (ad hominem attacks against philosophers of mind, commitment to a particular ontology of causation and personhood). Other commentators criticize my focus on ontology, also fallaciously, by arguing ad populum (few scientists are interested in it) and name-calling that misrepresents ontology as anti- scientific. Overall, none of the commentaries invalidates the target paper’s main point. Key words: mentalism, dualism, radical behaviorism Mentalism versus Dualism: Replies to Commentaries The commentaries to the target paper (Burgos, 2015) are insightful and stimulating. Some call for corrections to, others for further clarification of some specific claims, but none invalidates the target paper’s main point. Before my replies, it will be helpful to summarize the point: Contrary to what some radical behaviorists have claimed, mentalism (or cognitivism) is necessarily materialistic and, hence, cannot possibly be dualistic, not even “imply,” “invite,” “lead to,” or “open the door to” dualism. Nor can dualism coherently be a “form of mentalism,” or vice versa (cf. Lamal, 1993, p. 332). This point opposes radical behaviorists’ 1 I thank all the commentators for their insightful and stimulating remarks. I also thank Peter Killeen for many illuminating conversations about the topics discussed here. Correspondence should be addressed to [email protected]. 46 MENTALISM VS. DUALISM rejection of mentalism as inevitably, or possibly, dualistic. We could reject mentalism for several reasons, but dualism is not one of them. I use the term “dualism” in its standard philosophical sense to name the ontological view that divides reality into two fundamentally different kinds of entities (substances in Cartesian dualism, properties in property dualism): Material (or physical) versus immaterial (or nonphysical, or spiritual). In discussions of dualism thus formulated, “material” usually means to have extension in 3- dimensional space (length, breadth, and depth). On this use, only the physical- nonphysical duality is dualistic. Other dualities often regarded as necessarily “dualistic” (e.g., brain-body, objective-subjective, private-public) are not. Some (brain-body) cannot possibly be dualistic; others could be only if mind is nonphysical, but they do not commit us to this view. Mind can also be subjective and private, but still be physical. The most discussed form of dualism in this sense of the term is Cartesian dualism, after Descartes, who devised the so-called “Real Distinction Argument” to prove the division between a mind as an unextended (thinking) substance and a body as an extended (non-thinking) substance2. Mentalism too is an ontological view, or at least has a strong ontological aspect, in that some of its defining theses are about the nature of mind (e.g., causal power and internality). Hence the paper’s focus on ontological discussion: The ontological import of dualism and mentalism call for such a focus, even if the radical behaviorists’ rejections of both also have epistemological and linguistic aspects. However, these have been far more widely discussed than the ontological aspects, and can thus be safely put on hold for the purpose of thematic delimitation, for future discussion. Whatever they are, they will not invalidate the paper’s main point that mentalism cannot possibly be dualistic in the standard philosophical sense of the term. This point obtains even if mentalism suffers from the same epistemic and linguistic problems as dualism. Dualism’s epistemic and linguistic problems are not the same as, nor do they conversely entail, dualism. The point is much stronger than some mentalists’ (e.g., Fodor, 1968; Sperry, 1980) warning that they can be a materialists, or that mentalism and materialism are not mutually exclusive. Their warning allows for the possibility that a mentalist can be a dualist, or that mentalism and dualism are compatible, which is what worries radical behaviorists. They do not deny the possibility of materialistic mentalism, but they worry that it is uncomfortably close to dualistic mentalism. Mentalists themselves are partly guilty, for not seeking a final and complete break- up with dualism. The target paper does precisely that by arguing that mentalism and dualism are mutually exclusive. The expression “dualistic mentalism” (e.g., Moore, 2013; Schnaitter, 1984, p. 10; Terrace, 1984) thus becomes an oxymoron. So does “spiritualistic mentalism” 2 I distinguish between Descartes’ dualism and Cartesian dualism, following some authors’ (Baker & Morris, 1996) argument that the latter is a “caricature” (p. 159) of the former. Still, my focus is on the caricature, as it is the most familiar and discussed view, as distorting of Descartes’ real views as it might be. The caveat is that one must be careful not to identify Descartes’ with Cartesian dualism. 47 BURGOS (e.g., Mallot & Shane, 2016, p. 396), if “spiritual” means “immaterial” or “nonphysical.” And the expression “materialistic mentalism” (e.g., Mallot & Shane, 2016, p. 396) becomes redundant. Thus, contrary to Uttal’s (2004) metaphor, dualism is not a “sin” of mentalism. Rather, to paraphrase Fodor (1975, p. 4), confusing mentalism with dualism is the behaviorists’ sin; but then again, mentalists are partly guilty of promoting this confusion by implicitly allowing for a position such as dualistic mentalism. On the main target paper’s point, such a position is logically impossible. Not that “mentalism” is synonymous with “materialism,” as not all forms of materialism are mentalistic: Radical behaviorism is materialistic but antimentalistic (and antidualistic too). The proper labels, rather, are “mentalistic materialism” (or “mentalism,” for short) and “antimentalistic materialism” (or “antimentalism” for short; e.g., radical behaviorism). Allowing for the possibility of dualistic mentalism has made it harder for mentalists to articulate and defend their commitment to materialism. As a result, their positions tend to be highly unintuitive, biased (e.g., Fodor’s formulation and defense applies only to a form of functionalism), and misguided (e.g., Sperry mistook reductive materialism to exclude mentalism). Exactly how a mentalist can be a materialist, then, has never been quite clear. My argument for the impossibility of dualistic mentalism clarifies the matter in a more intuitive and unbiased way that allows for quite different, in fact opposed forms of mentalism (viz., mind-brain identity theory and functionalism). Mentalism cannot possibly be dualistic simply because two of its defining theses, mental causation and mind as internal (or internalism about the mind), are fundamentally inconsistent with dualism; hence the “versus” in the title. The other two defining theses, mind as subjective and nonbehavioral, are compatible with dualism but admit purely materialistic formulations that avoid dualism. In this summary, I focus on the first two theses. Descartes’ contemporaries Princess Elisabeth and Pierre Gassendi first pointed out the incompatibility between mental causation and dualism in their criticism of Cartesian dualism. This criticism has become the standard reason to reject Cartesian dualism in the philosophy of mind, and is echoed by radical behaviorists, often by asking rhetorically how something physical can cause or be caused by something nonphysical. Philosophers of mind nowadays often make the criticism in terms of the working hypothesis that physical reality is causally closed (i.e., physical events can only cause and be caused by physical events). This criticism does not apply to non-Cartesian forms of substance dualism, such as occasionalism and the theory of preestablished harmony, the precursors to today’s psychophysical parallelism (nondualistic forms of psychophysical parallelism are also possible). Although they keep a physical-nonphysical partition of substances (which defines Cartesian dualism), they reject mind-body causal interaction (also defining of Cartesian dualism). Nor does the criticism apply to another form of non-Cartesian dualism, Baruch Spinoza’s double-aspect theory, according to which the physical-nonphysical division is to be applied to aspects, not substances. 48 MENTALISM VS. DUALISM The contemporary form of Spinoza’s theory is property dualism, which divides properties (not substances) into physical and nonphysical. Property dualism has been argued for in terms of so-called “zombie argument,” which postulates the possibility of creatures that are physically (bodily, neurally, and behaviorally) identical to us but lack any phenomenal consciousness (feel nothing). This possibility has also been argued to imply epiphenomenalism, the negation of mental causation. If mental causation defines mentalism, property dualism cannot be a form of mentalism (nor can be non-Cartesian