habitual control over consciousness which prevented it from flaring into
all sorts of obsessions and agonies. Their bodies having become
deranged, their minds, far from correcting that derangement, instantly
share and betray it. A dream is always simmering below the conventional
surface of speech and reflection. Even in the highest reaches and
serenest meditations of science it sometimes breaks through. Even there
we are seldom constant enough to conceive a truly natural world;
somewhere passionate, fanciful, or magic elements will slip into the
scheme and baffle rational ambition.

A body seriously out of equilibrium, either with itself or with its
environment, perishes outright. Not so a mind. Madness and suffering can
set themselves no limit; they lapse only when the corporeal frame that
sustains them yields to circumstances and changes its habit. If they are
unstable at all, it is because they ordinarily correspond to strains and
conjunctions which a vigorous body overcomes, or which dissolve the body
altogether. A pain not incidental to the play of practical instincts may
easily be recurrent, and it might be perpetual if even the worst habits
were not intermittent and the most useless agitations exhausting. Some
respite will therefore ensue upon pain, but no magic cure. Madness, in
like manner, if pronounced, is precarious, but when speculative enough
to be harmless or not strong enough to be debilitating, it too may last
for ever.

An imaginative life may therefore exist parasitically in a man, hardly
touching his action or environment. There is no possibility of
exorcising these apparitions by their own power. A nightmare does not
dispel itself; it endures until the organic strain which caused it is
relaxed either by natural exhaustion or by some external influence.
Therefore human ideas are still for the most part sensuous and trivial,