Abstract
In recent years, due largely to the efforts of Karl Popper, the principle of falsification has come to the fore in discussions on the logic of the sciences and metaphysics. In its narrow form the principle may be put thus: a scientific theory can never be proved true, it can only be proved false. But it is commonly expanded into a wider form. This is done on the supposition that scientific knowledge is common–sense knowledge writ large. The principle now becomes: an assertion has a meaning and is significant only in so far as it is susceptible to empirical testing and so to being possibly shown false. In this general form the principle is proposed as a criterion for all genuine knowledge.