thus entirely under compulsion from without; it is driven to think
this or that, though for the moment it may not have the slightest
impulse or inclination to do so.

But when a man thinks for himself, he follows the impulse of his
own mind, which is determined for him at the time, either by his
environment or some particular recollection. The visible world of
a man's surroundings does not, as reading does, impress a _single_
definite thought upon his mind, but merely gives the matter and
occasion which lead him to think what is appropriate to his nature and
present temper. So it is, that much reading deprives the mind of all
elasticity; it is like keeping a spring continually under pressure.
The safest way of having no thoughts of one's own is to take up a book
every moment one has nothing else to do. It is this practice which
explains why erudition makes most men more stupid and silly than they
are by nature, and prevents their writings obtaining any measure of
success. They remain, in Pope's words:

_For ever reading, never to be read!_[1]

[Footnote 1: _Dunciad_, iii, 194.]

Men of learning are those who have done their reading in the pages of
a book. Thinkers and men of genius are those who have gone straight
to the book of Nature; it is they who have enlightened the world and
carried humanity further on its way. If a man's thoughts are to have
truth and life in them, they must, after all, be his own fundamental
thoughts; for these are the only ones that he can fully and wholly
understand. To read another's thoughts is like taking the leavings of
a meal to which we have not been invited, or putting on the clothes