We saw in Chapter 8 what consciousness is and how a naturalist like Armstrong might account for it. Traditionally, philosophers like Descartes and Hume thought of our minds like theatres of consciousness. All the contents of our minds were visible and transparent to us. Hume had this view of beliefs, describing them as vivid ideas associated with a present impression (1739: I, pt III, sec. 7). An impression is always a conscious experience, so beliefs as such are always conscious occurrences. When I believe that today is Wednesday, for instance, it is a conscious event in my mind, having a beginning, duration and an end.

The inadequacies of this account have been known for some time, but we saw that Ryle offered the classic demolition. Our ascription of belief, and understanding of the way beliefs work, just does not fit the model of beliefs as conscious episodes. If I consider how many beliefs a person may have at present, I would expect that they run at least into the thousands and probably hundreds of thousands. I doubt very much that anyone could be consciously thinking of so many different things simultaneously. Indeed it is most common that a person entertains only one thought at a time but it would be a very strange theory of belief that declared each person to have at most one belief at a time. Very often people are asleep, unconscious, or have their minds focused on an experience.