Andrew MacGregor (Glasgow)
"Sense-Data, Perceptual Variation and Acquaintance with the World"
Abstract: In The Problems of Philosophy Russell expounds his version of the sense-datum theory of perception, according to which the things of which we are directly aware are not mind-independent, physical objects but privately-accessible mind-dependent objects or sense-data.
There has recently been a resurgence of a view of perceptual experience diametrically opposed to sense-datum theory, viz the view that perceptual experience grants us direct acquaintance with worldly objects and properties. Such a view is central to naive realism as well as, less straightforwardly, some forms of intentionalism.
These quite different forms of direct realism are substantially shaped by the need to account for the possibility of illusory and hallucinatory experiences. Discussions of sense-datum theory have likewise often emphasised the role of illusory and hallucinatory experience in driving the theory’s conclusion that perception of worldly objects is mediated by mind-dependent entities. In TPoP, however, Russell focuses more on the variability of ordinary perceptual experience. His examples of perceptual variation were not always well chosen, but I will describe better examples which support his conclusion that the things of which we are directly aware are, to some extent, dependent for their nature on their being perceived.
Such examples arguably present greater difficulties for direct realism than illusion and hallucination. Nonetheless, I think direct realism – and especially naive realism – is well motivated by appeal to our pre-philosophical intuition that perception simply acquaints us directly with the world as it is. Russell himself refers to such intuitions as “instinctive beliefs” and argues for the philosophical importance of preserving and harmonising these beliefs as far as possible, while identifying those that we merely take to be instinctive because they have become “entangled” with genuinely instinctive beliefs.
How then can we reconcile the facts of perceptual variation with our “instinctive belief” about perception presenting the world as it is? I will suggest that such a reconciliation is possible although it will require the rejection of the claim that the nature of worldly things is wholly independent of how they appear to a subject. In other words, it will commit us to the idea that certain properties of worldly objects are constitutively determined by their perceptual relation to us as subjects. While this may sound like a form of idealism that Russell was explicitly reacting against, I will suggest how it might in fact be compatible with a purely physical ontology, albeit a relational or holistic one in which objects and their properties are dependent parts of the wider structures in which they participate.
Our orthodox view of the physical world as composed of objects constitutively independent from their relations to each other and – most pertinently – to physical subjects might seem like common sense and therefore fall into Russell’s category of “instinctive beliefs”. But I will suggest instead that this view of the physical is really a philosophical view which has become needlessly “entangled” in our more truly pre-philosophical intuition that we see things as they are.
An alternative, relational ontology has been endorsed by some philosophers in light of the findings of modern physics, and an ontology of this sort (e.g. ontic structural realism) might be the key to reconciling conscious experience and the physical world. Doing so will lead us to conclusions about the physical world that seem strange, but this seems forced on us anyway and, as Russell himself noted, “[t]he truth about physical objects must be strange” (TPoP p. 59).