Late Nineteenth into Twentieth Century 319concluded that the morphological and histological study of
the brains of idiots by Mierzejewski, Luys, and others were
... sufficient to prove, had we no other evidence, the fundamen-
tal truth of cerebro-mental pathology—the dependence of
healthy mind on healthy brain....We are surely justified in
expecting that by a prolonged examination of every part of the
brain structure, and the notation of the mental symptoms, we
shall arrive in future at more definite results; that the locality of
special disorders will be discovered, and that the correlation of
morbid mental and diseased cerebral states will become more
and more complete that the scientific classification of mental
maladies may be one day based upon pathological as well as
clinical knowledge, and psychology be founded, in part at
least, upon our acquaintance with the functions of the brain
(pp. 330–331).
Carl Wernicke (1848–1905), a German neurologist, also
assumed that pathology of the brain causes mental disorders,
the various symptoms being expressions of disorders of differ-
ent localized cerebral functions. Wernicke analyzed symptoms
of mental disorder as to whether their causes appeared to be
pathology in the sensory, the intrapsychic, or the motor sphere
of the brain. Meyer (1904) assessed Wernicke’s work as pure
empiricism with a rather artificial and not sufficiently founded
brain pathology and psychopathology. And in 1914, David C.
Thomson said, “The knowledge of the aetiology, pathology,
and therapeutics of insanity has advanced, and can only ad-
vance, on the fundamental view that the symptom-complex in-
sanity is a disorder or disease of the brain. I do not think this
can be asserted too often in these days of fads and ’isms, such
as faith-healing, Christian science, etc.” (p. 558).
However, various failures to relate specific psychopatho-
logical symptoms to specific lociof pathology in the brain
suggested that the cerebral problems in insanity were caused
by dynamic disturbances in function rather than lesions in the
brain structure. Nevertheless by the end of the nineteenth
century most members of the medical profession subscribed
to some variant of this view. They believed psychopathology
was caused by some biological disorder, inherited or ac-
quired, which affected the functioning of the central nervous
system, either by agency of the blood or because of lesions or
physiological malfunctioning, with increasing emphasis on
heredity.
Social Darwinism
Perhaps the most important nineteenth-century development
arose from the impact of Charles Darwin’s work. Evolu-
tionary theory and the conception of man as a descendant
of earlier animal forms were not totally unknown before
Darwin. However, the evidence he adduced was powerful
and his exposition was cogent. The clear consequences his
theory held for religious views of human nature and popular
views of man’s purpose in the cosmos created a dramatic and
disturbing departure from the thinking of earlier centuries.
Natural selection, with its message of competition and con-
flict was equally disturbing. Social Darwinism, a political in-
terpretation of the principle of natural selection, was to have
serious consequences for the public perception and treatment
of the mentally ill. Social Darwinism assumed that human
society was the product of inevitable and continuous conflict
and competition. As a result, individuals formed a continuum
of the “fit” (the intelligent, physically healthy, affluent, and
powerful) at one end and the “unfit” (poor, diseased, retarded,
insane, alcoholic, criminal, and powerless) at the other that
extended to the different “races” of man. The elimination of
unfit individuals or races was interpreted as part of man’s
inevitable process of progressive improvement with an ac-
companying moral imperative to eliminate any obstacles to
this improvement.Degeneracy TheoryOne theory that was compatible with Social Darwinism was
the theory of degeneration, which rested on the belief that a
wide variety of social ills were evidence of a unitary heredi-
tary defect. Physical disease (such as tuberculosis, deformed
bone development, etc.) and insanity, alcoholism, unemploy-
ment, poverty, and crime seemed to go hand in hand. In fam-
ilies and communities in which any of these were prevalent,
the others were likely to be found.
Dowbiggin (1985) reviewed the history of degeneracy
theory in France. The psychiatrist Jacques-Joseph Moreau
de Tours (1804–1884) asserted in 1859 that all insanity is
caused by an actual alteration of the central nervous system,
and that the major cause of insanity is genetic transmission
from parents to children of a neuropathic predisposition. He
argued that “large series of organs” such as the nervous
system, rather than “isolated traits,” are transmitted from
parents to offspring, and that susceptibility to disease, partic-
ularly mental derangement, is caused by a morbid deviation
from the healthy human type. However, autopsies of patients
with mental disease had failed to discover specific lesions
or pathological structures of the brain, suggesting that
the causes of insanity might not be biological. This led to the
theory that mental disease was caused by a hereditary degen-
eracy that results in a diffuse pathological functional disequi-
librium of the nervous system not detectable by autopsy.
Dowbiggin pointed out that the theory of morbid heredity
was compatible with the idea of free will. Dualism of soul and