Andrew MacGregor

I offer a novel defence of radically externalist theories of perception, via a strikingly spare and broadly physicalist metaphysics. The core, motivating claim is what I call a natural view of perception, according to which perception involves direct awareness of our environment, such that the phenomenology of experience consists of the worldly things perceived, as they appear to the perspective of the subject. To underpin this natural view, I propose a simple metaphysical picture of perception, which identifies the perceptual experience with the relation of awareness holding between subject and object, a relation that can be described in familiar physical terms as a causal process involving the thing perceived and the perceiver. Distinctively, the simple metaphysical picture has no place for the notion of ‘experiences’ understood as distinctively ‘mental’ states or events internal or otherwise belonging to the subject. Although there is some limited precedent for the simple metaphysical picture of perception, I offer the first detailed argument for its role in underpinning the natural view. The thesis offers new and detailed arguments to show that the simple metaphysical picture can not only account for normal perceptual experiences, but can also accommodate and explain other forms of sensory experience that have widely been considered to undermine the natural view of perception. These ‘problem’ cases include perceptual illusion, hallucination, and the role of memory and beliefs in influencing how things appear perceptually. In all of these cases, the simple metaphysical picture accounts for the phenomenology of the experience purely in terms of awareness of worldly objects, albeit in some cases objects that are not currently present in the subject’s environment. The simple metaphysical picture thus promises to explain not just perceptual experience but phenomenal consciousness more generally. The natural view is explicitly a commitment of some varieties of naïve realism, but I argue that the two theses come apart. For one thing, the simple metaphysical picture offers a solution to hallucination and other ‘problem’ cases quite different to the solutions offered by naïve realists. However, the most striking and novel claim advanced here is that the natural view can be defended without a commitment to realism. In this regard, I cite evidence for the subject-relativity or experience-dependence of certain perceived qualities, notably colour, and show the simple metaphysical picture allows us to square this with the natural view that colours are ‘out there’ in the environment. I discuss the metaphysical implications of rejecting realism while adhering to the simple metaphysical picture, and outline a radical – and radically simple – metaphysics of the world in general that might preserve the natural view and accommodate the simple metaphysical picture of phenomenal consciousness more generally. This metaphysics takes the form of a process monism in which the governing metaphysical structuring principle is one of top-down determination, such that whole processes determine the nature of their constituent parts