ed, to procure admission for the most evident
propositions into understandings frighted by their novelty, or hardened
against them by accidental prejudice; it can scarcely be conceived, how
frequently, in these extemporaneous controversies, the dull will be
subtle, and the acute absurd; how often stupidity will elude the force
of argument, by involving itself in its own gloom; and mistaken
ingenuity will weave artful fallacies, which reason can scarcely find
means to disentangle.

In these encounters the learning of the recluse usually fails him:
nothing but long habit and frequent experiments can confer the power of
changing a position into various forms, presenting it in different
points of view, connecting it with known and granted truths, fortifying
it with intelligible arguments, and illustrating it by apt similitudes;
and he, therefore, that has collected his knowledge in solitude, must
learn its application by mixing with mankind.

But while the various opportunities of conversation invite us to try
every mode of argument, and every art of recommending our sentiments, we
are frequently betrayed to the use of such as are not in themselves
strictly defensible: a man heated in talk, and eager of victory, takes
advantage of the mistakes or ignorance of his adversary, lays hold of
concessions to which he knows he has no right, and urges proofs likely
to prevail on his opponent, though he knows himself that they have no
force: thus the severity of reason is relaxed, many topicks are
accumulated, but without just arrangement or distinction; we learn to
satisfy ourselves with such ratiocination as silences others; and seldom
recall to a close examination, that discourse which has gratified our
vanity with victory and applause.

Some caution, therefore, must be used lest copiousness and facility be
made less valuable by inaccuracy and confusion. To fix the thoughts by
writing, and subject them to frequent examinations and reviews, is the
best method of enabling the mind to detect its own sophisms, and keep it
on guard against the fallacies which it practises on others: in
conversation we naturally diffuse our thoughts, and in writing we
contract them; method is the excellence of writing, and unconstraint the
grace of conversation.

To read, write, and converse in due proportions, is, therefore, the
business of a man of letters. For all these there is not often equal
opportunity; excellence, therefore, is not often att