8. Confirmation and Refutability

In the natural sciences a theory can be maintained only if it is in agreement with experimentally established facts. This agreement was, up to a short time ago, considered as confirmation. Karl Popper, in 1935, in Logik und Forschung3  pointed out that facts cannot confirm a theory; they can only refute it. Hence a more correct formulation has to declare: A theory cannot be maintained if it is refuted by the data of experience. In this way experience restricts the scientist’s discretion in constructing theories. A hypothesis has to be dropped when experiments show that it is incompatible with the established facts of experience.

It is obvious that all this cannot refer in any way to the problems of the sciences of human action. There are in this orbit no such things as experimentally established facts. All experience in this field is, as must be repeated again and again, historical experience, that is, experience of complex phenomena. Such an experience can never produce something having the logical character of what the natural sciences call “facts of experience.”

If one accepts the terminology of logical positivism and especially also that of Popper, a theory or hypothesis is “unscientific” if in principle it cannot be refuted by experience. Consequently, all a priori theories, including mathematics and praxeology, are “unscientific.” This is merely a verbal quibble. No serious man wastes his time in discussing such a terminological question. Praxeology and economics will retain their paramount significance for human life and action however people may classify and describe them.

The popular prestige that the natural sciences enjoy in our civilization is, of course, not founded upon the merely negative condition that their theorems have not been refuted. There is, apart from the outcome of laboratory experiments, the fact that the machines and all other implements constructed in accordance with the teachings of science run in the way anticipated on the ground of these teachings. The electricity-driven motors and engines provide a confirmation of the theories of electricity upon which their production and operation were founded. Sitting in a room that is lighted by electric bulbs, equipped with a telephone, cooled by an electric ran, and cleaned by a vacuum cleaner, the philosopher as well as the layman cannot help admitting that there may be something more in the theories of electricity than that up to now they have not been refuted by an experiment.

• 3Now also available in an English-language edition, The Logic of Scientific Discovery (New York, 1959).