Page:The Works of John Locke - 1823 - vol 01.djvu/81

 is sufficient to govern all our concernments. If we will disbelieve every thing, because we cannot certainly know all things, we shall do muchwhat as wisely as he, who would not use his legs, but sit still and perish, because he had no wings to fly.

§ 6. When we know our own strength, we shall the better know what to 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 any thing; or, on the other side, question every thing, 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. 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