Reason is man's particular and characteristic feature. There is no need for praxeology to raise the question whether reason is a suitable tool for the cognition of ultimate and absolute truth. It deals with reason only as far as it enables man to act.
All those objects which are the substratum of human sensation, perception, and observation also pass before the senses of animals. But man alone has the faculty of transforming sensuous stimuli into observation and experience. And man alone can arrange his various observations and experiences into a coherent system.
Action is preceded by thinking. Thinking is to deliberate beforehand over future action and to reflect afterwards upon past action. Thinking and acting are inseparable. Every action is always based on a definite idea about causal relations. He who thinks a causal relation thinks a theorem. Action without thinking, practice without theory are unimaginable. The reasoning may be faulty and the theory incorrect; but thinking and theorizing are not lacking in any action. On the other hand thinking is always thinking of a potential action. Even he who thinks of a pure theory assumes that the theory is correct, i.e., that action complying with its content would result in an effect to be expected from its teachings. It is of no relevance for logic whether such action is feasible or not.
It is always the individual who thinks. Society does not think any more than it eats or drinks. The evolution of human reasoning from the naive thinking of primitive man to the more subtle thinking of modern science took place within society. However, thinking itself is always an achievement of individuals. There is joint action, but no joint thinking. There is only tradition which preserves thoughts and communicates them to others as a stimulus to their thinking. However, man has no means of appropriating the thoughts of his precursors other than to think them over again. Then, of course, he is in a position to proceed farther on the basis of his forerunners' thoughts. The foremost vehicle of tradition is the word. Thinking is linked up with language and vice versa. Concepts are embodied in terms. Language is a tool of thinking as it is a tool of social action. [p. 178]
The history of thought and ideas is a discourse carried on from generation to generation. The thinking of later ages grows out of the thinking of earlier ages. Without the aid of this stimulation intellectual progress would have been impossible. The continuity of human evolution, sowing for the offspring and harvesting on land cleared and tilled by the ancestors, manifests itself also in the history of science and ideas. We have inherited from our forefathers not only a stock of products of various orders of goods which is the source of our material wealth; we have no less inherited ideas and thoughts, theories and technologies to which our thinking owes its productivity. But thinking is always a manifestation of individuals.