gs to it simply because he
loves it; when he hugs a delusion to his heart, this shows not mental
but moral obliquity; it is not insanity but self-deception, and it is by
no means of rare occurrence. In a well-reasoned article on "The
Metaphysics of Insanity," written by Mr. James M. Wilcox and printed in
the "American Catholic Quarterly Review" for January, 1878, some very
severe and no less true strictures are made upon the readiness of a vast
multitude of people to practise this wilful self-deception. "Self," he
writes (p. 54), "is the prolific origin of such errors; and so indulgent
are we to its faults that we try secretly to hide them even from our own
eyes, mostly with success; and where success is not perfect, we make a
second effort to hide the imperfection. Repeated efforts of this kind,
from which we but half turn away, are crowned in the end, and we soon
forget what successful hypocrites we have been. Our numerous passions,
the complexities of our desires, the tenacity of their grasp, and the
pleasant gentleness of its touch explain an infinity of temptations
followed by wilful successes in blindness, all of which are nothing less
than guilty acts of self-deception."

7. It oftens happens in real insanity that mental derangement manifests
itself upon one error or one group of errors only, while for all the
rest the patient appears to be quite rational. Such a man is called a
_monomaniac_. But he is truly an insane man; for the essence of insanity
is in him. It is usually found that a monomaniac will, sooner or later,
exhibit signs of mental unsoundness on other matters as well; and even
while he has given no such signs, it still remains true that a mind
cannot be trusted, but has something radically unsound about it, if it
is really unhinged at any point at all.

But then you must be very careful not to confound monomania with
eccentricity. The distinction is as important as it is real.
_Eccentricity_ is a conscious aberration from the common course of life;
it consists in peculiarities in reasoning, words, and actions, which are
wilfully indulged, in defiance of popular sentiment. The eccentric man
knows that he is eccentric; he is willing to be so, and to take the
consequences; but he is not insane.

As this matter is of frequent occurrence before the courts of justice,
and the validity of last wills in particular often depends on the view
that judges and expert witnesses take of it, I think it well to re