is brought on by the excitement of the
system being diminished: and this may proceed either from a
diminution of common stimulant powers, while the excitability is
sufficiently abundant, or it may proceed from an exhausted
excitability, while the stimulus is sufficiently abundant. The former
is called direct, and the latter indirect debility. The exciting
causes therefore of asthenic disease, first impair the functions,
then occasion a disturbed or inordinate action of them, giving many
of them a false appearance; some of them, for instance, appear to be
increased, for in hysteria and epilepsy, which are both diseases of
debility, the action of the muscles seems to be preternaturally
increased; but this depends chiefly on the accumulated excitability,
which gives such a degree of irritability to the system, that the
smallest irritation, whether external, such as heat, exercise, &c. or
internal, as emotions of the mind, excite a strong spasmodic action,
which brings on the symptoms of epilepsy and hysteria. This
inordinate action however soon exhausts the morbid excitability, and
thus suspends itself, a sleep often follows, from which the patient
wakes with only a general sense of languor and debility: but as the
same cause still remains, the excitability of the body again becomes
morbidly accumulated, and thus the slightest stimulus produces a
recurrence of the fit, and the tendency to return will increase with
its recurrence, so that at last the slightest imaginable cause will
produce it, on account of the power of habit and association.

Gout likewise appears like a sthenic disease, and in inflammation
takes place, which resembles pleurisy or peripneumony; but this
symptom is fallacious, for it depends on debility, and is only to be
cured by means, which in pleurisy and peripneumony, would produce
death.

Hence it must be evident that those phenomena of diseases, which we
call symptoms, are generally fallacious; but this may be owing to our
imperfect knowledge of the animal economy, so that we are not able to
explain or understand the manner in which they are produced: we ought
however carefully to guard against being misled by them in practice.
The great difficulty is to distinguish the nature of the disease,
whether it is sthenic or asthenic, or whether it depends on too great
excitement, or on debility; for this being once clearly ascertained,
we proceed with certainty in our mode of treatment, instead of the
ra