Online research in philosophy

In a number of places, Richard Swinburne has defended the logical possibility of perception without a body; and has inferred from this logical possibility that substance dualism is true. I challenge his defence of disembodied perception by arguing that a disembodied perceiver would not be able to distinguish between perceptions and hallucinations. I then claim that even if disembodied perception were possible, this could not be used to support substance dualism: such an inference would be either invalid or question-begging.

I attempt to rebut Dean Zimmerman's novel argument (2010), which he presents in support of substance dualism, for the conclusion that, in spite of its popularity, the combination of property dualism with substance materialism represents a precarious position in the philosophy of mind. I take issue with Zimmerman's contention that the vagueness of ‘garden variety’ material objects such as brains or bodies makes them unsuitable candidates for the possession of phenomenal properties. I also argue that the ‘speculative materialism’ that is available to a substance materialist property dualist who abandons the identification of persons with such garden variety objects is significantly more attractive than Zimmerman allows. Although I do not attempt to refute its substance dualist rival, I conclude that the combination of property dualism with substance materialism can withstand Zimmerman's objections.

Abstract Substance dualism is widely rejected by philosophers of mind, but many continue to accept some form of property dualism. The assumption here is that one can consistently believe that (1) mental properties are not physical properties, while denying that (2) mental particulars are not physical particulars. But is this assumption true? This paper considers several analyses of what makes something a physical particular (as opposed to a non-physical particular), and it is argued that on any plausible analysis, accepting (1) requires accepting (2) as well.

Like Aristotle, Thomas Aquinas holds that the rational soul is the substantial form of the human body. In so doing, he takes himself to be rejecting a Platonic version of substance dualism; his criticisms, however, apply equally to a traditional understanding of Cartesian dualism. Aquinas’s own peculiar brand of dualism is receiving increased attention from contemporary philosophers—especially those attracted to positions that fall between Cartesian substance dualism and reductive materialism. What Aquinas’s own view amounts to, however, is subject to debate. Philosophers (such as J. P. Moreland and Scott Rae) have claimed that ‘Thomistic substance dualism’ (TSD) centers around two beliefs: (1) the rational soul is an immaterial substance, and (2) this immaterial substance is the human person. In this paper, I argue that labeling such an account ‘Thomistic’ proves dangerously misleading—not only does Aquinas himself explicitly deny both of these claims, but he denies them for philosophically significant reasons. Furthermore, I argue that Aquinas’s own position provides an account of human nature both more coherent and philosophically attractive.

The mind-body problem is the problem of explaining how our mental states, events and processes—like beliefs, actions and thinking—are related to the physical states, events and processes in our bodies. A question of the form, ‘how is A related to B?’ does not by itself pose a philosophical problem. To pose such a problem, there has to be something about A and B which makes the relation between them seem problematic. Many features of mind and body have been cited as responsible for our sense of the problem. Here I will concentrate on two: the fact that mind and body seem to interact causally, and the distinctive features of consciousness. A long tradition in philosophy has held, with René Descartes, that the mind must be a non-bodily entity: a soul or mental substance. This thesis is called ‘substance dualism’ (or ‘Cartesian dualism’) because it says that there are two kinds of substance in the world, mental and physical or material. One reason for believing this is the belief that the soul, unlike the body, is immortal. Another reason for believing it is that we have free will, and this seems to require that the mind is a non-physical thing, since all physical things are subject to the laws of nature. To say that the mind (or soul) is a mental substance is not to say that the mind is made up of some non-physical kind of stuff or material. The use of the term ‘substance’ is rather the traditional philosophical use: a substance is an entity which has properties and persists through change in its properties. A tiger, for instance, is a substance, whereas a hurricane is not. To say that there are mental substances— individual minds or souls—is to say that there are objects which are non-material or non-physical, and these objects can exist independently of physical objects, like a person’s body. These objects, if they exist, are not made of non-physical ‘stuff’: they are not made of ‘stuff’ at all..

The enduring metaphysical question about minds and mental phenomena concerns their nature. At least since Descartes this question—the mind-body problem—has been understood in terms of the viability or necessity of mind-body dualism, the thesis that minds and bodies are essentially distinct kinds of substance. Assuming that the nonmental (‘body’) portions of the world are constituted of physical stuff, the remaining question is: Are minds or mental phenomena essentially distinct non-physical substances, or phenomena that essentially involve such distinct kinds of substances? By the middle of the Twentieth Century there was broad philosophical and scientific consensus that the answer to this classical question about minds is negative: Minds and mental phenomena are not essentially distinct substances, nor are they phenomena that essentially involve distinct kinds of substances. There are at least two broad trends and one specific argument that lead to this conclusion. One trend is the decreasing influence of specifically theological arguments and commitments in philosophical argumentation, so that religious belief in immortal souls was no longer given much weight in the ontology of mind. The second trend, perhaps related to the first, is the increased demand that metaphysical theories bear explanatory fruits, so that the postulation of an immaterial and essentially mental substance appears to be a abdication from explanatory duties rather than a useful proposal. The argument, known to Descartes from the very beginning, is that there has never been an adequate account of 1 how two essentially distinct and incompatible substances could causally interact.1 Descartes’ solution was inadequate and brute, and his followers struggled with the problem—leading to Leibniz’s parallelism and Malebranche’s occasionalism, among other views. The problem of mental causation, then, is the central difficulty that underines substance dualism.2 The negative answer on the question of substance dualism, however, only increases the pressure for some monistic account of the nature of minds..

Worries about mental causation are prominent in contemporary discussions of the mind and human agency. Originally, the problem of mental causation was that of understanding how a mental substance (thought to be immaterial) could interact with a material substance, a body. Most philosophers nowadays repudiate immaterial minds, but the problem of mental causation has not gone away. Instead, focus has shifted to mental properties. How could mental properties be causally relevant to bodily behavior? How could something mental qua mental cause what it does? After looking at the traditional Problem of Interaction, we survey various versions of the property-based problem and look at proposed solutions to them.

"Of Minds and Molecules" attempts to show the difficulties in mental-state brain-state monism. By exploring the differences in meaning between mental-state sentences and brain-state sentences, and by analysing the implications of the theory of the molecular composition of matter, a kind of dualism is arrived at that no scientist should feel uncomfortable with. It is a dualism without mental substance but it does not deprive mental states of their uniqueness. Arguments are given for the propriety of asserting causal connections and dependency relations between mental states and molecular states of the brain.

Despite the current resurgence of modest forms of mind-body dualism, traditional Cartesian immaterial-substance dualism has few if any defenders. This paper argues that no convincing case has been against substance dualism, and that standard objections to it can be credibly answered.