has been said that the development of the world proceeds under the
operation of the antagonistic principles of unity and individuality.
Unity, as a prior idea to individuality, which latter arises from the
disintegration of that which was formerly one--had, historically, a
prior development. The period of its paramount sway in the first grand
division of time stretches from the dawn of history up to about the
twelfth century, or to the beginning of the revival of learning. The
principle of individuality then began to be active, and has guided the
subsequent progress of civilization. At no time, nor in any nation,
however, has either one of these principles been entirely inactive. One
or the other has _preponderated_, and thus given distinct
characteristics to its age. It is to these preponderating drifts that
reference is made in the foregoing division, as specially marking
periods.

The opposite tendencies of unity and individuality, and their successive
development have been somewhat vaguely apprehended by Professor
Draper,--who has not, however, perceived them as _principles_,--and have
furnished him with the periods into which he arbitrarily divides the
progressive epochs of social growth. If we change these divisions into
their proper order--an order singularly disarranged by this author--we
shall have substantially the representative periods in the historical
domain, of unity and individuality. The order in which these eras are
placed in 'The Intellectual Development of Europe' is, 1, Age of
Credulity; 2, Age of Inquiry; 3, Age of Faith; 4, Age of Reason; 5, Age
of Decrepitude. It is evident, however, as partially shown by Mr.
Buckle, that the age of inquiry is uniformly subsequent to the age of
faith, and immediately precedes the age of reason. Comparing this
distribution, moreover, with the one given by Dr. Draper of the five
stages of human existence to which he makes it correspond, we find
childhood given as the age of inquiry, youth of faith, and manhood of
reason. The ages of inquiry and faith should, however, change places, in
order to be congruous. In applying these periods to the history of
Greece, the age of inquiry is made to extend from the rise of philosophy
to the time of Socrates; and the age of faith to comprise the epochs of
Socrates, Plato, and the Skeptics, up to about the time of Aristotle.
But in any such division as Dr. Draper attempts, the age of faith should
precede the rise of philosophica