est beginnings of most systems of Hindu thought
can be traced to some time between 600 B.C. to 100 or 200 B.C. It is
extremely difficult to say anything about the relative priority of the
systems with any degree of certainty. Some conjectural attempts have
been made in this work with regard to some of the systems, but how far
they are correct, it will be for our readers to judge. Moreover during
the earliest manifestation of a system some crude outlines only are
traceable. As time went on the systems of thought began to develop
side by side. Most of them were taught from the time in which they
were first conceived to about the seventeenth century A.D. in an
unbroken chain of teachers and pupils. Even now each system of
Hindu thought has its own adherents, though few people now

9

care to write any new works upon them. In the history of the growth of
any system of Hindu thought we find that as time went on, and as new
problems were suggested, each system tried to answer them consistently
with its own doctrines. The order in which we have taken the
philosophical systems could not be strictly a chronological one. Thus
though it is possible that the earliest speculations of some form of
Sa@mkhya, Yoga, and Mima@msa were prior to Buddhism yet they have been
treated after Buddhism and Jainism, because the elaborate works of these
systems which we now possess are later than Buddhism. In my opinion the
Vais'e@sika system is also probably pre-Buddhistic, but it has been
treated later, partly on account of its association with Nyaya, and
partly on account of the fact that all its commentaries are of a much
later date. It seems to me almost certain that enormous quantities of
old philosophical literature have been lost, which if found could have
been of use to us in showing the stages of the early growth of the systems
and their mutual relations. But as they are not available we have to be
satisfied with what remains. The original sources from which I have drawn
my materials have all been indicated in the brief accounts of the
literature of each system which I have put in before beginning the study
of any particular system of thought.

In my interpretations I have always tried to follow the original sources
as accurately as I could. This has sometimes led to old and unfamiliar
modes of expression, but this course seemed to me to be preferable to
the adoption of European modes of thought for the expression of Indian
ideas. But