Berkeley's Manifest Qualities Thesis

Berkeley's Manifest Qualities Thesis PHILLIP D. CUMMINS BERKELEY'S CONSTRUCTIVE presentation of immaterialism is built around a dualism of sensibles and spirits. Sensibles are perceived; they do not perceive. Spirits perceive; they are not themselves perceived. Spirits are substances and causes; sensibles are neither substances nor causes. Nothing is both a sensible and a spirit.' It is worth emphasizing what Berkeleian sensibles do not do. Most thoughtful persons would have no trouble listing many examples of things that they sense which they consider to perceive and act. For Berkeley, however, sensibles neither perceive nor perform any other mental activity. Moreover, they are inactive; that is why no sensible is ever a cause. It is worth considering his arguments for these claims, since examining the key principle upon which they rest reveals much about his philosophy. 1. SENSELESS INACTIVE SENSIBLES Berkeley endorses inferences from sensibles to perceivers and thinkers. However , although he employs arguments from states of sensibles to unsensed thoughts had by subjects logically distinct from those sensibles, he does not permit assigning such thoughts to the sensibles themselves. He is emphatic in claiming sensibles neither perceive nor think. Sensibles are senseless. To see why this is significant, consider an example. From watching someone fill in a crossword puzzle, one can, according to Berkeley, reasonably infer a process of thinking, but one cannot assign that thinking to the sensible whose behavior leads one to infer the thinking. To conclude from what one perceives that the This paper is the winner of the firstannual Colinand AlisaTurbayne International Berkeley EssayPrizeCompetition. ' Berkeley'sofficialdualism of spirits and sensiblesand the implicitmonism it concealsare discussed in my "Berkeley's Unstable Ontology."The Modern Schoolman 67 (1989): 15-3z. The roleof the ManifestQualitiesThesis in his metaphysicsis there touched upon, but not examined in detail. [385] 386 JOURNAL OF THE HISTORY OF PHILOSOPHY 28:3 JULY 1990 item being perceived is thinking, albeit imperceptibly, is for Berkeley a fundamental error. The numerical difference between the thinker one infers and the sensible one observes must always be preserved. This claim is problematic. If a sensible's observed states can support inferences to imperceptible thoughts, why cannot it be the very subject having those thoughts? If Berkeley is simply stipulating that by "spirit" he means non-sensible perceiver, he is entitled to the conclusion that spirits cannot be sensed and sensibles cannot be spirits. One is free, however, to challenge his stipulation. Notice, too, that it would not preclude sensibles which perceive or think; such perceiving or thinking sensibles could not, by Berkeley's definition, be called spirits, but that is beside the point. Were there sensibles which perceive or think, Berkeley's refusal to call them spirits could simply be ignored. Clearly, then, an argument is needed to establish the impossibility of perceiving or thinking, sensibles and so prove that sensibles are senseless. The materials for such an argument are found in Section 148 of Principles, where Berkeley writes, "A human spirit or person is not perceived by sense, as not being an idea; when therefore we see the colour, size, figure, and motions of a man, we perceive only certain sensations or ideas excited in our own minds: and these being exhibited to our view in sundry distinct collections, serve to mark out unto us the existence of finite and created spirits like ourselves. Hence it is plain, we do not see a man, if by man is meant that which lives, moves, perceives and thinks as we do. ''~ The argument seems to be that the person who lives, perceives, and thinks (the perceiver) cannot be identified with any sensible human body, because the latter is a collection of sensible qualities and because "when... we see the colour, size, figure, and motions of a man, we perceive only certain sensations or ideas excited in our own minds." No sensation or group of them, presumably, can be identified with a perceiver . The argument, with its seeming reduction of perceived human bodies to sensations or ideas, has strong idealistic overtones. The same seems to be true of Berkeley's argument for the essential inactivity of sensibles. An important assumption in Berkeley's philosophy is that whenever there is change...