by a single cause, becomes an ardent, and sometimes an undiscerning,
passion in the human mind.

Nothing shows the truth of this proposition more clearly than the
opinions of the ancients respecting their slaves. The most profound and
capacious minds of Rome and Greece were never able to reach the idea, at
once so general and so simple, of the common likeness of men, and of the
common birthright of each to freedom: they strove to prove that slavery
was in the order of nature, and that it would always exist. Nay, more,
everything shows that those of the ancients who had passed from the
servile to the free condition, many of whom have left us excellent
writings, did themselves regard servitude in no other light.

All the great writers of antiquity belonged to the aristocracy
of masters, or at least they saw that aristocracy established and
uncontested before their eyes. Their mind, after it had expanded itself
in several directions, was barred from further progress in this one; and
the advent of Jesus Christ upon earth was required to teach that all the
members of the human race are by nature equal and alike.

In the ages of equality all men are independent of each other, isolated
and weak. The movements of the multitude are not permanently guided
by the will of any individuals; at such times humanity seems always to
advance of itself. In order, therefore, to explain what is passing in
the world, man is driven to seek for some great causes, which, acting
in the same manner on all our fellow-creatures, thus impel them all
involuntarily to pursue the same track. This again naturally leads the
human mind to conceive general ideas, and superinduces a taste for them.

I have already shown in what way the equality of conditions leads every