THE SCIENTIFIC INVESTIGATOR 245 
than he could single-handed. He can not by himself answer the whole 
of his problem, but with the help of a corps of students, each prosecuting 
some particular part, he may be able to; and the students themselves 
gain by cooperating in such a unified project. For no one man has the 
ability to follow out all the clues that suggest themselves to his mind. 
And in the second place, a certain amount of teaching is almost neces- 
sary to prevent a man from becoming narrow, and to keep him in active 
touch with all sides of his subject. It is particularly important for an 
investigator to teach undergraduate courses, though these are the most 
difficult to present well, for that keeps him in touch with the broader 
and more generally comprehensible parts of his work. The occasional 
meeting with younger and fresher minds is stimulating, and clear 
presentation of a subject to them often clarifies our own ideas. It is 
probably on account of their teaching that university men are generally 
broader than museum curators. 
Given then the opportunity to measure the different paths of knowl- 
edge, and supposing a man has made his choice congenial and has 
resolved to stick to it, a great step has been taken. Yet this is, after all, 
merely the planting of the right seed in the proper ground, much re- 
mains before the harvest. To make the simile true we should imagine 
that the case is one where a man is at once seed, farmer and harvest, 
limited and constrained by his inherited powers. We have to find our 
particular effective seed, to set it out with care, and to keep its nurture 
mainly in our hands. 
The subject matter of a science can be taught us, but we have to 
learn to investigate mainly through our own endeavors. The teacher 
out of his experience can indicate a problem awaiting solution; he 
should be able to decide whether it be soluble, but the real work, the 
research, is with us. One can learn investigation only by investigation, 
and each man must find his own path through the maze. 
Encyclopedic knowledge is often more an impediment than a help 
to investigation; the two are contradictory. The student may become 
so charged with scholastic learning that he has no room left for think- 
ing. And as we recall the creative thinkers of the past, we find they 
were on the whole rather undertrained men, in consequence untired 
and active in thought, picking up knowledge only when it was needed. 
For knowledge is not an end but only a tool. Yet there still lingers the 
idea that during the three or four years the student devotes to his 
doctorate, he should try to learn the whole of his subject ! University 
teaching, it seems to me, should be called successful only when it helps 
a man to independent thinking. It is wholesome to recognize our 
limitations, to realize that we can not carry heavy freight and at the 
same time make headway. The mind that has to interpret must be 
fresh and agile, not loaded with the thousand and one opinions of fore- 
runners. Let us avoid burdening our strength with laborious compila- 
