The method of original investigation, strictly considered, presents
many difficulties. A long course of preliminary training--a thorough
knowledge of what has been done in a given field already--a quick
imagination--a genius for devising forms of apparatus which will enable
him to work well under particular conditions in the most simple and
effective way--the faculty of suspending judgment, and of seeing
what happens, all that happens, and just how it
happens--patience--caution--courage--quick judgment when a completed
experiment presses for an explanation--these are some of the
characteristics which must belong to the original worker.

Were we all capable of doing such work there would be these advantages,
among others, of studying for ourselves:

1. What we find out for ourselves we remember longer and recall more
readily than what we acquire in any other way. This advantage holds true
whether the facts learned are entirely new or only new to us. Almost
every man whose life has been spent in study has a store of facts which
he discovered, and on which he built hopes of future greatness until
he found out later that they were old to the knowledge of the world he
lived in. And these things are among those which will remain longest in
his memory.

2. Associated facts would be learned in studying in this way which would
remain unknown otherwise.

But all the advantages would be associated with disadvantages too. Long
periods of time would have to be given for comparatively small results.
The history of science is full of instances in which years were spent in