Mohamed Elsayed

This study deals with the issue of the verifiability principle and the different attempts made to revise it. The study begins with a historical perspective including some main trends of the philosophical movement which influenced the formulation of the principle and the thinking of the logical positivists in general. An explanation of the influence of Wittgenstein on the formulation of the verifiability principles follows in Chapter One. The influence is not clearly delineated and has been exaggerated by many commentators. ;Chapter Two considers the different formulations of the principle, as well as the objections posed against these formulations. This includes formulations and revisions by Carnap, Ayer, O'Connor, Rynin, Cohen and a host of others. ;Chapter Three examines the analytic-synthetic distinctions as the fundamental basis for formulation of the principle. This distinction was blurred by Quine's criticism, but an attempt is made to prove that Quine's criticism doesn't justify his rejection. Therefore, one can defend the tenability of the analytic-synthetic distinction on the basis of its useful value to help one understand the concept of knowledge. ;Chapter Four introduces the varied reasons for the failure of the previous formulations of the verifiability principle. It illustrates that the Positivist's claim of identifying "knowability" with "observability" is a mistake. It does not, however, describe the real way or method scientists use. In an effort to depart from the Positivist's small restrictive world, one needs to reconsider the meaning and range of human experience. This is a new modified version of the verifiability principle, which is dependent upon differentiation between two levels of language: the language of science and the language of metaphysical discourse. The study emphasizes that although one can distinguish between these two levels, one should also be aware that these levels are not self-contained systems and often intersect