Abstract

For some time there have been appearing in the philosophical literature hints and suggestions that the so-called “problem of the external world” should be abandoned, not primarily because it is of little pragmatic significance, but rather because there is really no such problem to be solved. The publication of Reichenbach's Experience and Prediction has now stimulated a resurgence of these suggestions. In the course of his discussion of the book in the April Philosophy of Science Professor Ernest Nagel has taken occasion to argue briefly that this problem, which Reichenbach attempts to solve, cannot even be stated unless one assumes its solution. And in a similar vein more recently Dr. William Barrett has also criticized Reichenbach and has then gone on to present certain fundamental logical considerations which, it is alleged, guarantee that the expression “Is there an external world?” cannot designate a legitimate philosophical problem. The situation, as he describes it, is as follows. The sentence “There is an external world” or the equivalent sentence “There is a physical object” can be confirmed in a physicalistic language only if one assumes the existence of certain physical objects. This procedure is of course circular. These sentences cannot therefore be confirmed, and, since the verifiability theory of meaning is accepted, the questions derived by transferring them into the interrogative mood cannot be meaningfully asked. A similar result is asserted to follow if one employs a perception language for science in place of a physicalistic language, since there is a parallelism between these two languages such that for every expression in the one there will be a corresponding expression in the other.