of centuries; and not only do the Upanishads and Pur[=a]nas represent
collectively many different periods, but exactly to which period each
individually is to be assigned remains always doubtful. Only in the
case of the Buddhistic writings is there a satisfactorily approximate
terminus a quo, and even here approximate means merely within the
limit of centuries.

Nevertheless, criteria fortunately are not lacking to enable one to
assign the general bulk of any one work to a certain period in the
literary development; and as these periods are, if not sharply, yet
plainly distinguishable, one is not in so desperate a case as he might
have expected to be, considering that it is impossible to date with
certainty any Hindu book or writer before the Christian era. For,
first, there exists a difference in language, demarcating the most
important periods; and, secondly, the development of the literature
has been upon such lines that it is easy to say, from content and
method of treatment, whether a given class of writings is a product of
the Vedic, early Brahmanic, or late Brahmanic epochs. Usually, indeed,
one is unable to tell whether a later Upanishad was made first in the
early or late Brahmanic period, but it is known that the Upanishads,
as a whole, _i.e._, the literary form and philosophical material which
characterize Upanishads, were earlier than the latest Brahmanic period
and subsequent to the early Brahmanic period; that they arose at the
close of the latter and before the rise of the former. So the
Br[=a]hmanas, as a whole, are subsequent to the Vedic age, although
some of the Vedic hymns appear to have been made up in the same period
with that of the early Br[=a]hmanas. Again, the Pur[=a]nas can be
placed with safety after the late Brahmanic age; and, consequently,
subsequent to the Upanishads, although it is probable that many
Upanishads were written after the first Pur[=a]nas. The general