By: Alushe Stafa
In 1967, John Passmore, a very well known historian of 20th - century philosophy, made this statement: “Logical positivism is dead, or as dead as a philosophical movement ever becomes” and much like him many other 21st century philosophers century uphold a very similar view. This view has been largely attributed to the vague concept of the positivist verification principle of significance and many other problems this principle generated that eventually caused the collapse of logical positivism. In this paper I will look at the verification principle, one of the central components of logical positivism, and argue that the positivist verification principle as a principle of factually significant discourse is not viable because of lack of general acceptance stemming from serious problems in its conception. Acceptance is crucial for scientific theory to be sustained. I will begin my paper by defining and illuminating the basic features of the positivist verification principle. Next, I will address the most significant problems with the criterion of significance and look at some counterexamples then show how the logical positivists addressed them. I will be especially concerned with the problems of applicability and verifiability that gave rise to the verification principle being abandoned by most philosophers. This opens the way for my final argument that the positivist verification theory is fundamentally flawed since it fails to meet its own criterion of variability.
The main element of logical positivism is what is known as the verifiability theory of meaning. The verification theory of meaning aims to determine what would make a sentence factually significant and thus meaningful. In the formulation of the principle logical positivists were motivated by the desire for clarity and precision in philosophical discourse. (1) A brief outline of the criterion of verifiability is given by A.J. Ayer in Language, Truth, Logic, the theory's most prominent defender:
“We say that a sentence is factually significant to any given person, if, and only if, he knows how to verify it the proposition which it purports to express – that is, if he knows what observations would be lead him, under certain conditions to accept the proposition as being true or reject it as being false” (16).
In other words the meaning of a proposition lies in its method of verification. The verifiability principle thus imposes a standard of empirical testability and factual significance on the propositions in philosophical theories. It also functions to distinguish the legitimate knowledge of science from speculative knowledge found in metaphysics seen by Ayer to be “neither true or false but literally senseless” (9). According to the logical positivists the verifiability criterion provides a definite solution for eliminating the superficial language of metaphysics and makes philosophy more in line with modern scientific thinking.
The logical positivists hold that there are only two classes of significant propositions. On the one hand, there are tautologies which express the truths of logic and mathematics derived from the axioms and definitions. Since tautologies do not make assertion about the empirical world, they cannot be disproven in experience. Ayer argues that “our knowledge that no observation can never confute the proposition ‘ 7+5 = 12’ depends on the fact that the symbolic expression ‘7+5’ is synonymous with ‘12’ (81). The logical positivists argue that tautologies are symbols that follow a certain convention and they do not express a priori knowledge of certain facts. They have no content. On the other hand, there are the factual propositions, the types of sentences whose validity is subject to the empirical verification. Any proposition that cannot be put into either of these categories is basically nonsensical. According to this thinking, the general statements/laws such as “arsenic is