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. - John Locke

For though the law of nature be plain and intelligible to all rational creatures; yet men, being biased by their interest, as well as ignorant for want of study of it, are not apt to allow of it as a law binding to them in the application of it to their particular cases.

govern his actions according to the dictates of the law of reason which God had implanted in him.

the UNDERSTANDING — who does not know that, as it is the most elevated faculty of the soul, so it is employed with a greater and more constant delight than any of the other. Its searches after truth are a sort of hawking and hunting, wherein the very pursuit makes a great part of the pleasure. Every step the mind takes in its progress towards Knowledge makes some discovery ... the understanding, like the eye, judging of objects only by its own sight, cannot but be pleased with what it discovers, having less regret for what has escaped it, because it is unknown. Thus he who has raised himself above the alms-basket, and, not content to live lazily on scraps of begged opinions, sets his own thoughts on work, to find and follow truth, will (whatever he lights on) not miss the hunter’s satisfaction; every moment of his pursuit will reward his pains with some delight; and he will have reason to think his time not ill spent, even when he cannot much boast of any great acquisition.