Page:The Works of John Locke - 1823 - vol 01.djvu/153

Ch. 4. as they are employed. The great difference that is to be found in the notions of mankind is from the different use they put their faculties to; whilst some (and those the most) taking things upon trust, misemploy their power of assent, by lazily enslaving their minds to the dictates and dominion of others in doctrines, which it is their duty carefully to examine, and not blindly, with an implicit faith, to swallow; others, employing their thoughts only about some few things, grow acquainted sufficiently with them, attain great degrees of knowledge in them, and are ignorant of all other, having never let their thoughts loose in the search of other inquiries. Thus, that the three angles of a triangle are equal to two right ones, is a truth as certain as any thing can be, and I think more evident than many of those propositions that go for principles; and yet there are millions, however expert in other things, who know not this at all, because they never set their thoughts on work about such angles; and he that certainly knows this proposition may yet be utterly ignorant of the truth of other propositions, in mathematics itself, which are as clear and evident as this, because, in his search of those mathematical truths, he stopped his thoughts short, and went not so far. The same may happen concerning the notions we have of the being of a Deity: for though there be no truth which a man may more evidently make out to himself than the existence of a God, yet he that shall content himself with things as he finds them, in this world, as they minister to his pleasures and passions, and not make inquiry a little farther into their causes, ends, and admirable contrivances, and pursue the thoughts thereof with diligence and attention, may live long without any notion of such a being. And if any person hath by talk put such a notion into his head, he may perhaps believe it; but if he hath never examined it, his knowledge of it will be no perfecter than his, who having been told that the three angles of a triangle