hands of the historian of science. In this matter the historian of science may be of great assistance to the psychologists among whom the discussions are being carried on; since, because of the analogy of the individual and the nation, the origin of a problem in the one may throw light on the similar process in the other.
This may be illustrated by numerous examples. Thus, some psychologists claim that the problems of science grow out of the practical needs of social and economic life. For example, to the primitive man the problem of catching the fish becomes real and definite because of his hunger. In like manner, the problem of the steam engine developed only after there was urgent need of such a machine for mining purposes; and the problem of the electric telegraph was defined by a marked social demand for a quick method of sending messages. The modern inventor finds the impulse to invention in his hope of gaining material reward for a more efficient machine, etc. But while this explanation of the origin of problems may do for those that fall within the realm of applied science, some think that it is not so useful when applied to the problems of pure science, like that of the motions of the solar system, the phenomena of universal gravitation, etc.
In order to account for the origin of this latter type of problem, it has been claimed that the prime factor in the definition of the problems that go to make up science is not to be found in the practical or concrete external situation, but rather in some internal ideal or desire or feeling with which an individual becomes inspired, he knows not how or whence. According to this view, an individual may notice an external phenomenon over and over again without its defining in him a problem. It is only when he notices in the phenomenon two or more factors that do not seem to him to be in harmony—not to accord with some cherished or imagined ideal—that a state of curiosity or of mental tension is induced; and when this condition is reached, he has a problem defined within him, which, if he have any real scientific spirit, does not suffer him to rest until his curiosity is satisfied or his mental tension eased. When this latter state is reached, he is said to have found an "explanation," and the problem is for him solved.
These statements are, of course, but the crudest possible descriptions of but two of the points of view from which the origin of problems has been approached. It will require considerable discussion and study before the whole matter will be cleared up in a tolerably satisfactory manner. But even though the question is far from settled, two important conclusions follow at once from either or both of the points of view just outlined. The first is this: Science is not the source of the progress of civilization. It is rather the faithful handmaid who helps us truly to satisfy the practical needs of society as they become manifest, and to achieve the purposes, ideals, or whatever they are, that