The same motives always produce the same actions. The same events follow
from the same causes. Ambition, avarice, self-love, vanity, friendship,
generosity, public spirit: these passions, mixed in various degrees, and
distributed through society, have been, from the beginning of the world,
and still are, the source of all the actions and enterprises, which have
ever been observed among mankind. Would you know the sentiments,
inclinations, and course of life of the Greeks and Romans? Study well
the temper and actions of the French and English: You cannot be much
mistaken in transferring to the former _most_ of the observations which
you have made with regard to the latter. Mankind are so much the same,
in all times and places, that history informs us of nothing new or
strange in this particular. Its chief use is only to discover the
constant and universal principles of human nature, by showing men in all
varieties of circumstances and situations, and furnishing us with
materials from which we may form our observations and become acquainted
with the regular springs of human action and behaviour. These records of
wars, intrigues, factions, and revolutions, are so many collections of
experiments, by which the politician or moral philosopher fixes the
principles of his science, in the same manner as the physician or
natural philosopher becomes acquainted with the nature of plants,
minerals, and other external objects, by the experiments which he forms
concerning them. Nor are the earth, water, and other elements, examined
by Aristotle, and Hippocrates, more like to those which at present lie
under our observation than the men described by Polybius and Tacitus are
to those who now govern the world.

Should a traveller, returning from a far country, bring us an account of
men, wholly different from any with whom we were ever acquainted; men,
who were entirely divested of avarice, ambition, or revenge; who knew no
pleasure but friendship, generosity, and public spirit; we should