their
most sinister quality is a horrible clarity of detail; a connecting of
one thing with another in a map more elaborate than a maze. If you argue
with a madman, it is extremely probable that you will get the worst of
it; for in many ways his mind moves all the quicker for not being
delayed by the things that go with good judgment. He is not hampered by
a sense of humour or by charity, or by the dumb certainties of
experience. He is the more logical for losing certain sane affections.
Indeed, the common phrase for insanity is in this respect a misleading
one. The madman is not the man who has lost his reason. The madman is
the man who has lost everything except his reason.

The madman's explanation of a thing is always complete, and often in a
purely rational sense satisfactory. Or, to speak more strictly, the
insane explanation, if not conclusive, is at least unanswerable; this
may be observed specially in the two or three commonest kinds of
madness. If a man says (for instance) that men have a conspiracy against
him, you cannot dispute it except by saying that all the men deny that
they are conspirators; which is exactly what conspirators would do. His
explanation covers the facts as much as yours. Or if a man says that he
is the rightful King of England, it is no complete answer to say that
the existing authorities call him mad; for if he were King of England
that might be the wisest thing for the existing authorities to do. Or if
a man says that he is Jesus Christ, it is no answer to tell him that the
world denies his divinity; for the world denied Christ's.

Nevertheless he is wrong. But if we attempt to trace his error in exact
terms, we shall not find it quite so easy as we had supposed. Perhaps
the nearest we can get to expressing it is to say this: that his mind
moves in a perfect but narrow circle. A small circle is quite as
infinite as a large circle; but, though it is quite as infinite, it is
not so large. In the same way the insane explanation is quite as
complete as the sane one, but it is not so large. A bullet is quite as
round as the world, but it is not the world. There is such a thing as a
narrow universality; there is such a thing as a small and cramped
eternity; you may see it in many modern religions. Now, speaking quite
externally and empirically, we may say that the strongest and most
unmistakable _mark_ of madness is this combination between a logical
completeness and a spiritual contractio