The Evidence of the Senses

Abstract

I return to an ancient philosophical question: What kind of evidence is provided by senses? Many will feel, I'm sure, that there is nothing new to be said about this question. And perhaps they are right. But, given present state of philosophy, something, even if it is nothing new, needs to be said about it. For there is still a great deal of confusion about nature of perceptual evidence. The most unfortunate confusion, I think, gives rise to belief that there are no serious problems about perceptual evidence and that, once one sees that this is so, other problems of traditional theory of knowledge will disappear. typical attitude was that of members of Vienna Circle. Carnap, for example, saw need of referring to one's total evidence when speaking of practical application of inductive logic and theory of probability.' But so far as concept of evidence itself is concerned, he felt that it was sufficient to say that evidence that a person possesses is total knowledge of results of his observations. One is led to ask, then, what Carnap meant by the results of one's observations. In his writings on probability, he gives us no answer to this question. And if we look back to his earlier writings on verification, we seem to have traveled in a circle. For he there says, not that application of probability presupposes concept of observational knowledge, but that concept of observational knowledge presupposes application of probability. He writes, for example: A predicate 'P' of a language L is called observable for an organism (e.g., a person) N, if, for suitable arguments,