undertake with hopes of success; and when we have well surveyed the
POWERS of our own minds, and made some estimate what we may expect from
them, we shall not be inclined either to sit still, and not set our
thoughts on work at all, in despair of knowing anything; nor on the
other side, question everything, and disclaim all knowledge, because
some things are not to be understood. It is of great use to the sailor
to know the length of his line, though he cannot with it fathom all the
depths of the ocean. It is well he knows that it is long enough to reach
the bottom, at such places as are necessary to direct his voyage, and
caution him against running upon shoals that may ruin him. Our business
here is not to know all things, but those which concern our conduct. If
we can find out those measures, whereby a rational creature, put in
that state in which man is in this world, may and ought to govern his
opinions, and actions depending thereon, we need not to be troubled that
some other things escape our knowledge.


7. Occasion of this Essay.

This was that which gave the first rise to this Essay concerning the
understanding. For I thought that the first step towards satisfying
several inquiries the mind of man was very apt to run into, was, to take
a survey of our own understandings, examine our own powers, and see to
what things they were adapted. Till that was done I suspected we began
at the wrong end, and in vain sought for satisfaction in a quiet and
sure possession of truths that most concerned us, whilst we let loose
our thoughts into the vast ocean of Being; as if all that boundless
extent were the natural and undoubted possession of our understandings,
wherein there was nothing exempt from its decisions, or that escaped
its comprehension. Thus men, extending their inquiries beyond their