A library may be very large; but if it is in disorder, it is not so
useful as one that is small but well arranged. In the same way, a man
may have a great mass of knowledge, but if he has not worked it up
by thinking it over for himself, it has much less value than a far
smaller amount which he has thoroughly pondered. For it is only when a
man looks at his knowledge from all sides, and combines the things he
knows by comparing truth with truth, that he obtains a complete hold
over it and gets it into his power. A man cannot turn over anything in
his mind unless he knows it; he should, therefore, learn something;
but it is only when he has turned it over that he can be said to know
it.

Reading and learning are things that anyone can do of his own free
will; but not so _thinking_. Thinking must be kindled, like a fire
by a draught; it must be sustained by some interest in the matter
in hand. This interest may be of purely objective kind, or merely
subjective. The latter comes into play only in things that concern
us personally. Objective interest is confined to heads that think by
nature; to whom thinking is as natural as breathing; and they are very
rare. This is why most men of learning show so little of it.

It is incredible what a different effect is produced upon the mind
by thinking for oneself, as compared with reading. It carries on and
intensifies that original difference in the nature of two minds which
leads the one to think and the other to read. What I mean is that
reading forces alien thoughts upon the mind--thoughts which are as
foreign to the drift and temper in which it may be for the moment, as
the seal is to the wax on which it stamps its imprint. The mind is