"define instinct as an inherited or innate psycho-physical disposition which determines its possessor to perceive,
and to pay attention to, objects of a certain class, to experience an emotional excitement of a particular quality upon
perceiving such an object, and to act in regard to it in a particular manner, or, at least, to experience an impulse to
such action."^4 If these definitions are less than illuminating, Freud's formulation is outstanding in its unclarity.
Freud writes of "instinct" as "a borderland concept between the mental and the physical, being both the mental
representative of the stimuli emanating from within the organism and penetrating to the mind, and at the same time
a measure of the demand made upon the energy of the latter in consequence of its connection with the body."^5 In
spite of the central role that instincts play in his system, this is as close as Freud ever comes to a definition.
That mysterious force, "instinct," is not a thought or an action or an emotion or a need. The attempt, on the part of
some theorists, to identify an instinct as a "compound reflex" has been recognized as unsupportable and has
collapsed. A reflex is a specific, definable neurophysiological phenomenon, the existence of which is empirically
demonstrable; it is not a dumping ground for un-understood behavior.^6
To account for man's actions in terms of undefinable "instincts" is to contribute nothing to human knowledge: it is
only to confess that one does not know why man acts as he does. To observe that men engage in sexual activities
and to conclude that man has a "sex instinct"—to observe that men seek food when they are hungry and to conclude
that man has a "hunger instinct"—to observe that some men act destructively and to conclude that man has a
"destructive instinct"—to observe that men usually seek out one another's company and to conclude that man has a
''gregarious instinct"—is to explain nothing. It is merely to place oneself in the same epistemological category as
the physician in the anecdote who "explains" to a distraught mother that the reason why her child will not drink
milk is that "the child is just not a milk-drinker."
The history of instinct theory, in the past fifty years, is the history of intense efforts, on the part of its supporters, to
twist the meaning of language, of their formulations and of the facts of reality, in order to protect their doctrines
from science's growing recognition that traits and activities alleged to be "instinctive" are