Philip Goff

In the recent metaphysics literature, a number of philosophers have independently endeavoured to marry sparse ontology to abundant truth. The aim is to keep ontological commitments minimal, whilst allowing true sentences to quantify over a vastly greater range of entities than those which they are ontologically committed to. For example, an ontological commitment only to concrete, microscopic simples might be conjoined with a commitment to truths such as ‘There are twenty people working in this building’ and ‘There are prime numbers greater than 5.’ I argue that a significant challenge to this project comes from the philosophy of mind. As Theodore Sider has pointed out, anti-physicalism is consistent with a sparse ontology. However, I will try to show that the premises of the standard anti-physicalist arguments can be used to form an argument to the conclusion that sentences which quantify over subjects of experience ontologically commit us to subjects of experience. Truths about consciousness cannot be bought more cheaply than their superficial grammar suggests.

How do we account for resemblance between concrete particular objects? What is it about reality which makes a sentence such as the following true? (1) x and y are both spherical Realists about properties claim that, at a fundamental level, this sentence is true because x and y both exemplify the property of sphericity. Michael Loux favours this account of resemblance. Nevertheless, Loux concedes that austere nominalism, which I understand to be the view that nothing exists over and above particular concrete objects, can offer a plausible account of resemblance.

Realism about cognitive or semantic phenomenology, the view that certain conscious states are intrinsically such as to ground thought or understanding, is increasingly being taken seriously in analytic philosophy. The principle aim of this paper is to argue that it is extremely difficult to be a physicalist about cognitive phenomenology. The general trend in later 20th century/early 21st century philosophy of mind has been to account for the content of thought in terms of facts outside the head of the thinker at the time of thought, e.g. in terms of causal relations between thinker and world, or in terms of the natural purposes for which mental representations have developed. However, on the assumption that consciousness is constitutively realised by what is going on inside the head of a thinker at the time of experience, the content of cognitive phenomenology cannot be accounted for in this way. Furthermore, any internalist account of content is particularly susceptible to Kripkensteinian rule following worries. It seems that if someone knew all the physical facts about what is going on in my head at the time I was having a given experience with cognitive phenomenology, they would not thereby know whether that state had ‘straight’ rather than ‘quus-like’ content, e.g. whether the experience was intrinsically such as the ground the thought that two plus two equals four or intrinsically such as to ground the thought that two quus two equals four. The project of naturalising consciousness is much harder for realists about cognitive phenomenology.

A zombie is a physical duplicates of a human being which lacks consciousness. A ghost is a phenomenal duplicate of a human being whose nature is exhausted by consciousness. Discussion of zombie arguments, that is anti-physicalist arguments which appeal to the conceivability of zombies, is familiar in the philosophy of mind literature, whilst ghostly arguments, that is, anti-physicalist arguments which appeal to the conceivability of ghosts, are somewhat neglected. In this paper I argue that ghostly arguments have a number of dialectical advantages over zombie arguments. I go onto explain how the conceivability of ghosts is inconsistent with two kinds of a priori physicalism: analytic functionalism and the Australian physicalism of Armstrong and Lewis

Zombies are bodies without minds: creatures that are physically identical to actual human beings, but which have no conscious experience. Much of the consciousness literature focuses on considering how threatening philosophical reflection on such creatures is to physicalism. There is not much attention given to the converse possibility, the possibility of minds without bodies, that is, creatures who are conscious but whose nature is exhausted by their being conscious. We can call such a ‘purely conscious’ creature a ghost.

Dualists say plausible things about our mental concepts: there is a way of thinking of pain, in terms of how it feels, which is independent of causal role. Physicalists make attractive ontological claims: the world is wholly physical. The attraction of a posteriori physicalism is that it has seemed to do both: to agree with the dualist about our mental concepts, whilst retaining a physicalist ontology. In this paper I argue that, in fact, a posteriori physicalism departs from the dualist's intuitive picture of our phenomenal concepts in just as radical a manner as more traditional forms of physicalism. Whereas the physicalism of David Lewis and David Armstrong is counterintuitive in holding that our only way of thinking about pain is in terms of its causal role, the physicalism of David Papineau and Brian Loar departs from common sense in holding that our phenomenal concept of pain is opaque: thinking of pain in terms of how it feels reveals nothing of what it is for something to feel pain. The arguments of David Chalmers and Frank Jackson against a posteriori physicalism involve general claims about all concepts. In contrast, my argument makes a claim only about phenomenal concepts: phenomenal concepts are not opaque