be changed suddenly by occular sensation, or
reason. Yet great perseverance in the frequently presenting contrary ideas
will sometimes slowly remove this hallucination, or in great length of time
oblivion, or forgetfulness, performs a cure, by other means in vain
attempted.

23. _Tabes imaginaria._ This imaginary disease, or hallucination, is caused
by the supposed too great frequency of parting with the semen, and had long
imposed upon the physician as well as the patient, till Mr. John Hunter
first endeavoured to shew, that in general the morbid effects of this
pollution was in the imagination; and that those were only liable to those
effects in general, who had been terrified by the villainous books, which
pretend to prevent or to cure it, but which were purposely written to vend
some quack medicine. Most of those unhappy patients, whom I have seen, had
evidently great impression of fear and self-condemnation on their minds,
and might be led to make contradictory complaints in almost any part of the
body, and if their confessions could be depended on, had not used this
pollution to any great excess.

M. M. 1. Assure them if the loss of the semen happens but twice a week, it
will not injure them. 2. Marry them. The last is a certain cure; whether
the disease be real or imaginary. Cold partial bath, and astringent
medicines frequently taken, only recal the mind to the disease, or to the
delinquency; and thence increase the imaginary effects and the real cause,
if such exists. Mr. ---- destroyed himself to get free from the pain of
fear of the supposed ill consequences of self-pollution, without any other
apparent disease; whose parents I had in vain advised to marry him, if
possible.

24. _Sympathia aliena._ Pity. Our sympathy with the pleasures and pains of
others distinguishes men from other animals; and is probably the foundation
of what is termed our moral sense and the source of all our virtues. See
Sect. XXII. 3. 3. When our sympathy with those miseries of mankind, which
we cannot alleviate, rises to excess, the mind becomes its own tormentor;
and we add to the aggregate sum of human misery, which we ought to labour
to diminish; as in the following eloquent lamentation from Akenside's
Pleasures of Imagination, Book II. 1. 200.

----------------Dark,
As midnight storms, the scene of human things
Appear'd before me; deserts, burning sands,
Where the parch'd adder dies; the frozen south;
And desolatio