were impossible to collect any general observations concerning mankind;
and no experience, however accurately digested by reflection, would ever
serve to any purpose. Why is the aged husbandman more skilful in his
calling than the young beginner but because there is a certain
uniformity in the operation of the sun, rain, and earth towards the
production of vegetables; and experience teaches the old practitioner
the rules by which this operation is governed and directed.

66. We must not, however, expect that this uniformity of human actions
should be carried to such a length as that all men, in the same
circumstances, will always act precisely in the same manner, without
making any allowance for the diversity of characters, prejudices, and
opinions. Such a uniformity in every particular, is found in no part of
nature. On the contrary, from observing the variety of conduct in
different men, we are enabled to form a greater variety of maxims, which
still suppose a degree of uniformity and regularity.

Are the manners of men different in different ages and countries? We
learn thence the great force of custom and education, which mould the
human mind from its infancy and form it into a fixed and established
character. Is the behaviour and conduct of the one sex very unlike that
of the other? Is it thence we become acquainted with the different
characters which nature has impressed upon the sexes, and which she
preserves with constancy and regularity? Are the actions of the same
person much diversified in the different periods of his life, from
infancy to old age? This affords room for many general observations
concerning the gradual change of our sentiments and inclinations, and
the different maxims which prevail in the different ages of human
creatures. Even the characters, which are peculiar to each individual,
have a uniformity in their influence; otherwise our acquaintance with