Sam Coleman

Stephen Yablo suggested that the relation of mental properties to physical properties is the same as that between red and scarlet: one of determinable property to determinate property. So just as being scarlet is a specific way of being red, on Yablo’s proposal a subject’s having a certain neurological property (c-fibres firing, say) is a specific way of a subject’s having a certain mental property (pain, in this case). I explain the virtues of this theory, in particular as defended and developed by Jessica Wilson, but raise some problems for it. I then describe a novel theory of the mental/physical relationship, which inverts the Yablo-Wilson proposal. On this theory mental properties, notably phenomenal properties – or, as I will say, qualia – are determinates of determinable physical properties. I explain the virtues of this view, and argue that they at least match, and plausibly exceed, those of the Yablo-Wilson theory. In particular, this new theory is able to account for certain prominent perplexities of the mind/body problem that tend to go unexplained. I distinguish the view from nearby theories, in particular the increasingly popular ‘Russellian monism’. I end by likening it to a recent interpretation of Aristotle’s philosophy of mind due to David Charles.

Barbara Montero and Sam Coleman address the question of whether a life that involves psychedelic drug use can be meaningful and answer in the affirmative. Specifically, they contend that, on the conception of life’s meaning they defend, which they call “meaning-of-life externalism” (the view that the meaningfulness of one’s life is, at least partly, but essentially, a function of the relation between the content of one’s of mind, on the one hand, and truth and reality, on the other), the use of psychedelics, in appropriate contexts, is no bar to, but can contribute to, a meaningful life. They argue that, because psychedelics alter one’s perception in such a way as to leave both the world and one’s contact with it intact, the use of such drugs does not render one’s life any less meaningful. In making this case they contrast the clinical use of psychedelics with the prospect of sustained engagement in virtual reality (VR), recently discussed by Chalmers, which (as they put it) “does impede one’s ability to lead a meaningful life in the externalist sense because VR, in contrast to psychedelics, changes the world yet holds experience constant.” What is key for life’s meaning, then, is engagement with external reality.

David Pitt argues that whereas conscious thinking must be understood in qualitative terms, unconscious processes that feed into thought and cognition can be modelled without this commitment — hence without positing unconscious qualitative characters. Qualityfree neural-computational processes, instead, perform the functions we would have expected genuine unconscious mentality to fulfil, so Pitt suggests. I argue, against Pitt, that we need to extend the qualitative conception of mental content, especially thought content, to the unconscious. The core reason I give is that the phenomenal intentionalist critique of causal naturalist approaches to content, that accounts of content in terms of causation cannot capture the determinacy of conscious thought, applies also to Pitt's attempt to do without unconscious qualitative characters when modelling the unconscious processes that feed into conscious thought and cognition. Phenomenal intentionalists are right that only mental qualities can enable the mind–brain to dice contents and content-related operations sufficiently finely as to capture the way cognition actually works. Hence, as well as a quality of conscious thought we must posit qualities of unconscious thought. A thoroughgoing phenomenal intentionalism, thus, in view of the role of unconscious cognition in mental life overall, needs to posit unconscious qualitative characters, notably of thought.

Conscious mental qualities, aka phenomenal qualities, are seemingly a leading factor in much of our behaviour. Pains make us recoil from painful stimuli, itches make us scratch, feelings of anger sometimes make us shout, visually perceiving red leads us to halt at stop lights, and so on. To relinquish this claim about the efficacy of conscious mental qualities would mean surrendering a major component of our everyday, intuitive self-conception; hence, the claim enjoys considerable prima facie plausibility. Unconscious mental qualities, however, have been posited by a mere handful of philosophers historically, and are nowadays almost universally rejected. Via a case study of ‘restless legs syndrome’, I argue that there is a hitherto unnoticed cost to this prevailing rejection of unconscious mental qualities: the causal efficacy of conscious mental qualities is threatened. In fact, I argue, we face a dilemma: To endorse epiphenomenalism about conscious mental qualities, or to posit unconscious mental qualities. Since it is so plausible that conscious mental qualities are causally efficacious, this reasoning constitutes an argument for unconscious mental qualities. Moving beyond the sensory case, I explain how analogous reasoning might apply to other mental faculties where phenomenal qualities seem causally involved: notably, emotions and mental imagery.