action tel ou tel muscle, un seul ou plusieurs muscles a la fois,
lorsqu il a voulu que les signes caracteristiques des passions, meme
les plus fugaces, fussent ecrits passagerement sur la face de l homme.
Ce langage de la physionomie une fois cree, il lui a suffi, pour le
rendre universel et immuable, de donner a tout etre humain la faculte
instinctive d exprimer toujours ses sendments par la contraction des
memes muscles.
Many writers consider the whole subject of Expression as inexplicable.
Thus the illustrious physiologist Muller, says,[17] The completely
different expression of the features in different passions shows that,
according to the kind of feeling excited, entirely different groups of
the fibres of the facial nerve are acted on. Of the cause of this we
are quite ignorant.
No doubt as long as man and all other animals are viewed as independent
creations, an effectual stop is put to our natural desire to
investigate as far as possible the causes of Expression. By this
doctrine, anything and everything can be equally well explained; and it
has proved as pernicious with respect to Expression as to every other
branch of natural history. With mankind some expressions, such as the
bristling of the hair under the influence of extreme terror, or the
uncovering of the teeth under that of furious rage, can hardly be
understood, except on the belief that man once existed in a much lower
and animal-like condition. The community of certain expressions in
distinct though allied species, as in the movements of the same facial
muscles during laughter by man and by various monkeys, is rendered
somewhat more intelligible, if we believe in their descent from a
common progenitor. He who admits on general grounds that the structure
and habits of all animals have been gradually evolved, will look at the
whole subject of Expression in a new and interesting light.
The study of Expression is difficult, owing to the movements being
often extremely slight, and of a fleeting nature. A difference may be
clearly perceived, and yet it may be impossible, at least I have found
it so, to state in what the difference consists. When we witness any
deep emotion, our sympathy is so strongly excited, that close
observation is forgotten or rendered almost impossible; of which fact I
have had many curious proofs. Our imagination is another and still more
serious source of error; for if from the nature of the circumstances we
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