body, the art of curing and preserving the body should be so much
sought after, and the invention of it, as being so useful, should be
ascribed to the immortal Gods; but the medicine of the mind should not
have been so much the object of inquiry while it was unknown, nor so
much attended to and cultivated after its discovery, nor so well
received or approved of by some, and accounted actually disagreeable,
and looked upon with an envious eye by many? Is it because we, by means
of the mind, judge of the pains and disorders of the body, but do not,
by means of the body, arrive at any perception of the disorders of the
mind? Hence it comes that the mind only judges of itself when that very
faculty by which it is judged is in a bad state. Had nature given us
faculties for discerning and viewing herself, and could we go through
life by keeping our eye on her--our best guide--there would be no
reason certainly why any one should be in want of philosophy or
learning; but, as it is, she has furnished us only with some feeble
rays of light, which we immediately extinguish so completely by evil
habits and erroneous opinions that the light of nature is nowhere
visible. The seeds of virtues are natural to our constitutions, and,
were they suffered to come to maturity, would naturally conduct us to a
happy life; but now, as soon as we are born and received into the
world, we are instantly familiarized with all kinds of depravity and
perversity of opinions; so that we may be said almost to suck in error
with our nurse's milk. When we return to our parents, and are put into
the hands of tutors and governors, we are imbued with so many errors
that truth gives place to falsehood, and nature herself to established
opinion.

II. To these we may add the poets; who, on account of the appearance
they exhibit of learning and wisdom, are heard, read, and got by heart,
and make a deep impression on our minds. But when to these are added