events of such
a man's life are managed by his own wisdom and prudence; and that greater
pleasure cannot be derived from an eternity of life than such a man enjoys
from this life which we see to be limited.

But in your dialectics he thought that there was no power which could
contribute either to enable men to live better, or argue more
conveniently. To natural philosophy he attributed a great deal of
importance. For by the one science it is only the meaning of words and the
character of a speech, and the way in which arguments follow from or are
inconsistent with one another, that can be seen; but if the nature of all
things is known, we are by that knowledge relieved from superstition,
released from the fear of death, exempted from being perplexed by our
ignorance of things, from which ignorance horrible fears often arise.
Lastly, we shall be improved in our morals when we have learnt what nature
requires. Moreover, if we have an accurate knowledge of things, preserving
that rule which has fallen from heaven as it were for the knowledge of all
things, by which all our judgments of things are to be regulated, we shall
never abandon our opinions because of being overcome by any one's
eloquence.

For unless the nature of things is thoroughly known, we shall have no
means by which we can defend the judgments formed by our senses. Moreover,
whatever we discern by our intellect, all arises from the senses. And if
our senses are all correct, as the theory of Epicurus affirms, then
something may be discerned and understood accurately; but as to those men
who deny the power of the senses, and say that nothing can be known by
them, those very men, if the senses are discarded, will be unable to
explain that very point which they are arguing about. Besides, if all
knowledge and science is put out of the question, then there is an end
also of all settled principles of living and of doing anything.

Thus, by means of natural philosophy, courage is desired to withstand the
fear of death, and constancy to put aside the claims engendered by
superstition; and by removing ignorance of all secret things, tranquillity
of mind is produced; and by explaining the nature of desires and their
different kinds, we get moderation: and (as I just now explained) by means
of this rule of knowledge, and of the judgment which is established and
corrected by it, the power of distinguishing truth from falsehood is put
into man's hands.

XX. There