Chapter VII Of Simple Ideas of both Sensation and Reflection 1. Ideas of pleasure and pain. There be other simple ideas which convey themselves into … - John Locke

Hence it comes to pass, that a man, who is very sober, and of right understanding in all other things, may in one particular be as frantic, as any in Bedlam; if either by any sudden very strong impression, or long fixing his fancy upon one sort of thoughts, incoherent ideas have been cemented together so powerfully, as to remain united. But there are degrees of madness, as of folly; the disorderly jumbling ideas together, is in some more, and some less. In short, herein seems to lie the difference between idiots and madmen, That madmen put wrong ideas together, and so make wrong propositions, but argue and reason right from them: but idiots make very few or no propositions, and reason scarce at all.

To love truth for truth's sake is the principal part of human perfection in this world, and the seed-plot of all other virtues.

The great and cheif end, therefore, of men uniting into commonwealths, and putting themselves under government, is the preservation of their property; to which in the state of Nature there are many things wanting