ver the wide earth, will
seek his like in vain, and offer a palpable contrast with everyone
else in virtue of his unmistakable distinction. Nay, more: were he,
like the wandering Jew, to live through several generations, he would
still remain in the same superior position. If this were not so, it
would be difficult to see why his thoughts should not perish like
those of other men.

_Metaphors_ and _similes_ are of great value, in so far as they
explain an unknown relation by a known one. Even the more detailed
simile which grows into a parable or an allegory, is nothing more than
the exhibition of some relation in its simplest, most visible and
palpable form. The growth of ideas rests, at bottom, upon similes;
because ideas arise by a process of combining the similarities and
neglecting the differences between things. Further, intelligence, in
the strict sense of the word, ultimately consists in a seizing of
relations; and a clear and pure grasp of relations is all the more
often attained when the comparison is made between cases that lie wide
apart from one another, and between things of quite different nature.
As long as a relation is known to me as existing only in a single
case, I have but an _individual_ idea of it--in other words, only an
intuitive knowledge of it; but as soon as I see the same relation in
two different cases, I have a _general_ idea of its whole nature, and
this is a deeper and more perfect knowledge.

Since, then, similes and metaphors are such a powerful engine of
knowledge, it is a sign of great intelligence in a writer if his
similes are unusual and, at the same time, to the point. Aristotle
also observes that by far the most important thing to a writer is
to have this power of metaphor; for it is a gift which cannot be
acquired, and it is a mark of genius.

As regards _reading_, to require that a man shall retain everything he
has ever read, is like asking him to carry about with him all he has
ever eaten. The one kind of food has given him bodily, and the other
mental, nourishment; and it is through these two means that he has
grown to be what he is. The body assimilates only that which is like
it; and so a man retains in his mind only that which interests him, in
other words, that which suits his system of thought or his purposes in
life.

If a man wants to read good books, he must make a point of avoiding
bad ones; for life is short, and time and energy limited.

_Repetitio est mat