intellectual existence is the desire to ascertain and
communicate truth, a sort of positive and negative electricity
immediately establishes itself between those who want to know and those
who desire to communicate their knowledge; and the connection is
mutually agreeable until these two desires are satisfied. When this
happens, the connection naturally ceases; but the memory of it usually
leaves a permanent feeling of good-will, and a permanent disposition to
render services of the same order. This, in brief, is the whole
philosophy of the subject; but it may be observed farther, that the
purely intellectual intercourse which often goes by the name of
friendship affords excellent opportunities for the formation of real
friendship, since it cannot be long continued without revealing much of
the whole nature of the associates.

We do not easily exhaust the mind of another, but we easily exhaust what
is accessible to us in his mind; and when we have done this, the first
benefit of intercourse is at an end. Then comes a feeling of dulness and
disappointment, which is full of the bitterest discouragement to the
inexperienced. In maturer life we are so well prepared for this that it
discourages us no longer. We know beforehand that the freshness of the
mind that was new to us will rapidly wear away, that we shall soon
assimilate the fragment of it which is all that ever can be made our
own, so we enjoy the freshness whilst it lasts, and are even careful of
it as a fruiterer is of the bloom upon his grapes and plums. It may seem
a hard and worldly thing to say, but it appears to me that a wise man
might limit his intercourse with others before there was any danger of
satiety, as it is wisdom in eating to rise from table with an appetite.
Certainly, if the friends of our intellect live near enough for us to
anticipate no permanent separation by mere distance, if we may expect to
meet them frequently, to have many opportunities for a more thorough and
searching exploration of their minds, it is a wise policy not to exhaust
them all at once. With the chance acquaintances we make in travelling,
the case is altogether different; and this is, no doubt, the reason why
men are so astonishingly communicative when they never expect to see
each other any more. You feel an intense curiosity about some temporary
companion; you make many guesses about him; and to induce him to tell
you as much as possible in the short time you are likely t