This latter method of entering into the passions of others is rendered of
very extensive use by the pleasure we take in imitation, which is every day
presented before our eyes, in the actions of children, and indeed in all
the customs and fashions of the world. From this our aptitude to imitation,
arises what is generally understood by the word sympathy so well explained
by Dr. Smith of Glasgow. Thus the appearance of a cheerful countenance
gives us pleasure, and of a melancholy one makes us sorrowful. Yawning and
sometimes vomiting are thus propagated by sympathy, and some people of
delicate fibres, at the presence of a spectacle of misery, have felt pain
in the same parts of their own bodies, that were diseased or mangled in the
other. Amongst the writers of antiquity Aristotle thought this aptitude to
imitation an essential property of the human species, and calls man an
imitative animal. [Greek: To zôon mimômenon].

These then are the natural signs by which we understand each other, and on
this slender basis is built all human language. For without some natural
signs, no artificial ones could have been invented or understood, as is
very ingeniously observed by Dr. Reid. (Inquiry into the Human Mind.)

VIII. The origin of this universal language is a subject of the highest
curiosity, the knowledge of which has always been thought utterly
inaccessible. A part of which we shall however here attempt.

Light, sound, and odours, are unknown to the foetus in the womb, which,
except the few sensations and motions already mentioned, sleeps away its
time insensible of the busy world. But the moment he arrives into day, he
begins to experience many vivid pains and pleasures; these are at the same
time attended with certain muscular motions, and from this their early, and
individual association, they acquire habits of occurring together, that are