2. Certain Knowledge

Radical empiricism rejects the idea that certain knowledge concerning the conditions of the universe is accessible to the minds of mortal men. It considers the a priori categories of logic and mathematics as assumptions or conventions, freely chosen on account of their convenience for the attainment of the kind of knowledge that man is able to acquire. All that is inferred by deduction from these a priori categories is merely tautological and does not convey any information about the state of reality.

3. The Uncertainty of the Future

According to an often quoted dictum of Auguste Comte, the objective of the—natural—sciences is to know in order to predict what will happen in the future. These predictions are, as far as they refer to the effects of human action, conditional. They say: If A, then B. But they do not tell anything about the emergence of A. If a man absorbs potassium cyanide, he will die. But whether he will swallow this poison or not is left undecided.

4. Quantification and Understanding in Acting and in History

Many data with which the mind is concerned either in retrospect or in planning for the future can be expressed in numerical terms. Other relevant magnitudes can only be put into words of a nonmathematical language. In regard to such magnitudes the specific understanding of the sciences of human action is a substitute, as it were, for the unfeasibility of measurement.

5. The Precariousness of Forecasting in Human Affairs

In forecasting what may or will happen in the future, man can either be right or mistaken. But his anticipation of future events cannot influence the course of nature. Whatever man may expect, nature will go its own way unaffected by any human expectations, desires, wishes, and hopes.

6. Economic Prediction and the Trend Doctrine

Economics can predict the effects to be expected from resorting to definite measures of economic policies. It can answer the question whether a definite policy is able to attain the ends aimed at and, if the answer is in the negative, what its real effects will be. But, of course, this prediction can be only “qualitative.” It cannot be “quantitative” as there are no constant relations between the factors and effects concerned. The practical value of economics is to be seen in this neatly circumscribed power of predicting the outcome of definite measures.

7. Decision-making

There are fads and fashions in the treatment of scientific problems and in the terminology of the scientific language.

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.

9. The Examination of Praxeological Theorems

The epistemologist who starts his lucubrations from the analysis of the methods of the natural sciences and whom blinders prevent from perceiving anything beyond this field tells us merely that the natural sciences are the natural sciences and that what is not natural science is not natural science. About the sciences of human action he does not know anything, and therefore all that he utters about them is of no consequence.