those by Mr. Wolf of the Cynopithecus, were first reproduced by Mr.
Cooper on wood by means of photography, and then engraved: by this
means almost complete fidelity is ensured.
CHAPTER I. GENERAL PRINCIPLES OF EXPRESSION.
The three chief principles stated The first principle Serviceable
actions become habitual in association with certain states of the mind,
and are performed whether or not of service in each particular case The
force of habit Inheritance Associated habitual movements in man Reflex
actions Passage of habits into reflex actions Associated habitual
movements in the lower animals Concluding remarks.
I will begin by giving the three Principles, which appear to me to
account for most of the expressions and gestures involuntarily used by
man and the lower animals, under the influence of various emotions and
sensations.[101] I arrived, however, at these three Principles only at
the close of my observations. They will be discussed in the present and
two following chapters in a general manner. Facts observed both with
man and the lower animals will here be made use of; but the latter
facts are preferable, as less likely to deceive us. In the fourth and
fifth chapters, I will describe the special expressions of some of the
lower animals; and in the succeeding chapters those of man. Everyone
will thus be able to judge for himself, how far my three principles
throw light on the theory of the subject. It appears to me that so many
expressions are thus explained in a fairly satisfactory manner, that
probably all will hereafter be found to come under the same or closely
analogous heads. I need hardly premise that movements or changes in any
part of the body, as the wagging of a dog s tail, the drawing back of a
horse s ears, the shrugging of a man s shoulders, or the dilatation of
the capillary vessels of the skin, may all equally well serve for
expression. The three Principles are as follows.
I. _The principle of serviceable associated Habits_. Certain complex
actions are of direct or indirect service under certain states of the
mind, in order to relieve or gratify certain sensations, desires, &c.;
and whenever the same state of mind is induced, however feebly, there
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