critical moments enables a transition to be made toward new methodologies. Also the discoveries of the practical understanding provide the raw material necessary for the success of the speculative Reason. But when all allowance has been made for this interplay of the two functions, there remains the essential distinction between operations of Reason governed by the purposes of some external dominant interest, and operations of Reason governed by the immediate satisfaction arising from themselves. For example, truthfulness as an element in one’s own self-respect issues from a reverence for Reason in its own right. Whereas truthfulness as a dodge usually necessary for a happy life depends upon the notion of Reason as serving alien purposes. Sometimes these two grounds for truthfulness are at issue with each other. It may happen that the moral issues depending on the latter ground for immediate truthfulness, or for its abandonment, may be superior to those depending on the former ground. But the point of immediate interest is that these two grounds for truthfulness bear witness to the two functions of Reason.
The history of the practical Reason must be traced back into the animal life from which mankind emerged. Its span is measured in terms of millions of years, if we have regard to the faint sporadic flashes of intelligence which guided the slow elaboration of methods. A survey of species seems to show that a customary method soon supersedes the necessity for such flashes of progress. In this way
