13. Difference between idiots and madmen.
In fine, the defect in naturals seems to proceed from want of
quickness, activity, and motion in the intellectual faculties, whereby they are deprived of reason; whereas
madmen, on the other side, seem to suffer by the other extreme. For they do not appear to me to have lost the
faculty of reasoning, but having joined together some ideas very wrongly, they mistake them for truths; and they
err as men do that argue right from wrong principles. For, by the violence of their imaginations, having taken their
fancies for realities, they make right deductions from them. Thus you shall find a distracted man fancying himself
a king, with a right inference require suitable attendance, respect, and obedience: others who have thought
themselves made of glass, have used the caution necessary to preserve such brittle bodies. Hence it comes to pass
that a man who is very sober, and of a 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.