motional type of melancholia.

_Hysteria_ is a nervous disorder based upon suggestibility, and capable
of imitating most known diseases.

_Insane impulses_ are morbid demands for reckless action beyond the
control of the will.

Example: The impulse to kill, quite regardless of who may be the victim.

_Psychopathic personality_ is a term much used today to designate an
hereditary tendency on the part of the individual to mental disorder.

The _neuropath_ is the individual with an inborn tendency to the
neurosis.

_Neurotic_ is a term broadly employed for the nervous in whom emotions
predominate over reason.

_Neurasthenia_ is a nervous disorder characterized by undue
fatiguability.

_Psychasthenia_ is a nervous disorder characterized by a sense of
unreality, weakness of will, self-accusation, and usually by phobias and
obsessions, all subject to temporary correction by reason or influence
from without.

_Hypochondriasis_ is a disorder characterized by morbid attention to
bodily sensations, and insistent ideas of bodily disorder.

_Phobia_ is a morbid fear or dread.

FACTORS CAUSING VARIATIONS FROM NORMAL MENTAL PROCESSES

HEREDITY

When we consider the accumulated possibilities for disorder which the
family tree of almost any one of us can show, the wonder is not that
there are so many nervous or insane, but rather that any come within
hailing distance of the normal. For multitudes are born of parents whose
bodies were food poisoned or alcohol or drug poisoned, and whose nervous
systems were tense and irritable, oversensitive, and suffering from the
effect of these same toxins on the brain. Others are of manic-depressive
parentage; some are possibly even of paranoic or dementia praecox
lineage; while many of our finest and best had psychopathic or
neuropathic heredity. Syphilis, itself, and the underpower bodies of
tuberculosis are heritages of many.

When we realize, too, that we are born with certain inherent tendencies
of temperament, which are too often of the melancholic or overcholeric
type, our wonder grows that we are not doomed to defeat at birth. Were
it not for the possibilities in the germ-plasm of choosing the much of
good also in our heredity, often enough to overbalance the bad, and for
the proved power of environment and training to modify or even
altogether overcome the harmful parts of our birthright, there would be
little hope for many.

ENVIRONMENT

While environment may prov