246 THE POPULAR SCIENCE MONTHLY 
tion. We sometimes think we are getting wise when we are only get- 
ting 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 antenne, 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 work- 
ing 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. 
