in him, in consequence of the different combinations, of the various
modifications, which this matter, diversified in itself, undergoes in
his machine. Thus, in one, the blood is superabundant; in another, the
bile; in a third, phlegm, &c.

It is from Nature--from his parents--from causes, which from the first
moment of his existence have unceasingly modified him, that man derives
his temperament. It is in his mother's womb that he has attracted the
matter which, during his whole life, shall have an influence on his
intellectual faculties--on his energies--on his passions--on his
conduct. The very nourishment he takes, the quality of the air he
respires, the climate he inhabits, the education he receives, the ideas
that are presented to him, the opinions he imbibes, modify this
temperament. As these circumstances can never be rigorously the same in
every point for any two men, it is by no means surprising that such an
amazing variety, so great a contrariety, should be found in man; or that
there should exist as many different temperaments, as there are
individuals in the human species.

Thus, although man may bear a general resemblance, he differs
essentially, as well by the texture of his fibres and the disposition of
his nerves, as by the nature, the quality, the quantity of matter that
gives them play, that sets his organs in motion. Man, already different
from his fellow, by the elasticity of his fibres, the tension of his
nerves, becomes still more distinguished by a variety of other
circumstances: he is more active, more robust, when he receives
nourishing aliments, when he drinks wine, when he takes exercise: whilst
another, who drinks nothing but water, who takes less juicy nourishment,
who languishes in idleness, shall be sluggish and feeble.