tion. We sometimes think we are getting wise when we are only getting rusty.
It is this consideration that indicates a man should receive very little help with his doctor's thesis, he should sink or swim without the help of a convenient raft—or professor. For then is the witching time when he is finding out whether he holds the power of research, and he alone can tell whether he has it; he can tell by a certain elation and undefined feeling of strength. The student should be given a soluble problem for his thesis, also certain technical aid, then left rather severely to his own devices. If he succeed he will have proved his ability; if he fail it is still well, for he will be saved from an ill-chosen career. While, on the other hand, the result of aid constantly given is what we may call the "one-thesis man," he who finishes his thesis, to be sure, and gets his degree, but who afterwards, when he is thrown upon himself, proves unable to carry out further investigation. The best test of a leader of a school of investigation is not the number of doctors graduated, but the number who afterwards actively continue to investigate. For their own good students should prosecute their problems so far as possible without extraneous help.
The highest that graduate work can foster is independent thinking, not scholastic learning. A man may be led to knowledge, but he can not be made to think.
There are three particular gifts that the investigator should cherish to his utmost, imagination, judgment and the maintenance of an ideal.
As the insect stretches out his antennae, feeling and smelling at once, forming thereby an idea of what is ahead of him, so it is that by the help of our imagination we can reach out into the unknown. Blind searching for a clue is not profitable, and it is waste of time to expect some happy fortune to bring an answer to us. Science is not a game of chance. It is necessary to form tentative explanations, and the working hypothesis is the outcome of the imagination much more than of the reason. The reason deals with the known and experienced, it is the imagination that must as a pioneer leap into the unknown. Thus the scientist makes his soundings and feels the depths. He has to forecast various possibilities, and to test these severally. Yet the imagination is only a feeler and not a leg to stand upon. We must bear in mind that hypotheses are but suggestions, invaluable though they be in directing effort, and that the real labor of the scientist is the testing of his hypotheses. The immediate subject matter of all of us, physicist, mathematician, chemist, philologist, whatever our calling may be, is hypothesis, and out of hypotheses we have to reach explanations; an explanation so attained is a theory. We must not confuse hypothesis with theory, nor inflict upon suffering colleagues, much less publish, all our hypotheses. If, as Goethe says, all theory is gray, how colorless must hypothesis be until it has been turned to account.
