The natural sciences are ultimately based on facts as established by laboratory experiment. Physical and biological theories are confronted with these facts, and are rejected when in conflict with them. The perfection of these theories no less than the improvement of technological and therapeutical procedures requires more and better laboratory research. These experimental ventures absorb time, painstaking effort of specialists, and costly expenditure of material. Research can no longer be conducted by isolated and penniless scientists, however ingenious.

The early economists devoted themselves to the study of the problems of economics. In lecturing and writing books they were eager to communicate to their fellow citizens the results of their thinking. They tried to influence public opinion in order to make sound policies prevail in the conduct of civic affairs. They never conceived of economics as a profession.

When the businessmen finally learned that the boom created by credit expansion cannot last and must necessarily lead to a slump, they realized that it was important for them to know in time the date of the break. They turned to economists for advice.

Tax-supported universities are under the sway of the party in power. The authorities try to appoint only professors who are ready to advance ideas of which they themselves approve. As all nonsocialist governments are today firmly committed to interventionism, they appoint only interventionists.

In countries which are not harassed by struggles between various linguistic groups public education can work if it is limited to reading, writing, and arithmetic. With bright children it is even possible to add elementary notions of geometry, the natural sciences, and the valid laws of the country. But as soon as one wants to go farther, serious difficulties appear. Teaching at the elementary level necessarily turns into indoctrination. It is not feasible to represent to adolescents all the aspects of a problem and to let them choose between dissenting views.

Economics must not be relegated to classrooms and statistical offices and must not be left to esoteric circles. It is the philosophy of human life and action and concerns everybody and everything. It is the pith of civilization and of man’s human existence.

To mention this fact is not to indulge in the often derided weakness of specialists who overate the importance of their own branch of knowledge. Not the economists, but all the people today assign this eminent place to economics.

The paramount role that economic ideas play in the determination of civic affairs explains why governments, political parties, and pressure groups are intent upon restricting the freedom of economic thought. They are anxious to propagandize the “good” doctrine and to silence the voice of the “bad” doctrines. As they see it, truth has no inherent power which could make it ultimately prevail solely by virtue of its being true. In order to carry on, truth needs to be backed by violent action on the part of the police or other armed troops.

We have concluded that the value of each unit of any good is equal to its marginal utility at any point in time, and that this value is determined by the relation between the actor’s scale of wants and the stock of goods available. We know that there are two types of goods: consumers’ goods, which directly serve human wants, and producers’ goods, which aid in the process of production eventually to produce consumers’ goods. It is clear that the utility of a consumers’ good is the end directly served. The utility of a producers’ good is its contribution in producing consumers’ goods.

Factors of production are valued in accordance with their anticipated contribution in the eventual production of consumers’ goods. Factors, however, differ in the degree of their specifity, i.e., the variety of consumers’ goods in the production of which they can be of service. Certain goods are completely specific—are useful in producing only one consumers’ good. Thus, when, in past ages, extracts from the mandrake weed were considered useful in healing ills, the mandrake weed was a completely specific factor of production—it was useful purely for this purpose.