Some years ago, there was published a book in the German language with the title L.T.I. These three letters stood for three Latin words, lingua Tertii Imperii, the language of the Third Reich. And the author, a former professor of Romance languages at one of the German universities, described in this book his adventures during the Nazi regime.

[This article is excerpted from chapter 14 of Human Action.] It is generally believed that economists, in dealing with the problems of a market economy, are quite unrealistic in assuming that all men are always eager to gain the highest attainable advantage. They construct, it is said, the image of a perfectly selfish and rationalistic being for whom nothing counts but profit.

[From Socialism: An Economic and Sociological Analysis, by Ludwig von Mises, pp. 113–22.] All human action, so far as it is rational, appears as the exchange of one condition for another. Men apply economic goods and personal time and labour in the direction which, under the given circumstances, promises the highest degree of satisfaction, and they forego the satisfaction of lesser needs so as to satisfy the more urgent needs. This is the essence of economic activity — the carrying out of acts of exchange.12

[Adapted from Chapter 2 of Human Action.] The study of all the data of experience concerning human action is the scope of history. The historian collects and critically sifts all available documents. On the ground of this evidence he approaches his genuine task.

The Revolt Against Reason. It is true that some philosophers were ready to overrate the power of human reason. They believed that man can discover by ratiocination the final causes of cosmic events, the inherent ends the prime mover aims at in creating the universe and determining the course of its evolution.

All doctrines that have sought to discover in the course of human history some definite trend in the sequence of changes have disagreed, in reference to the past, with the historically established facts and where they tried to predict the future have been spectacularly proved wrong by later events.