far as it was understood in those days. But the most important
achievement of Indian thought was philosophy. It was regarded as the goal
of all the highest practical and theoretical activities, and it indicated
the point of unity amidst all the apparent diversities which the complex
growth of culture over a vast area inhabited by different peoples produced.

It is not in the history of foreign invasions, in the rise of independent
kingdoms at different times, in the empires of this or that great monarch
that the unity of India is to be sought. It is essentially one of
spiritual aspirations and obedience to the law of the spirit, which were
regarded as superior to everything else, and it has outlived all the
political changes through which India passed.

The Greeks, the Huns, the Scythians, the Pathans and the Moguls who
occupied the land and controlled the political machinery never ruled
the minds of the people, for these political events were like hurricanes
or the changes of season, mere phenomena of a natural or physical order
which never affected the spiritual integrity of Hindu culture. If after
a passivity of some centuries India is again going to become creative it
is mainly on account of this fundamental unity of her progress and
civilisation and not for anything that she may borrow from other
countries. It is therefore indispensably necessary for all those who
wish to appreciate the significance and potentialities of Indian culture
that they should properly understand the history of Indian philosophical
thought which is the nucleus round which all that is best and highest in
India has grown. Much harm has already been done by the circulation of
opinions that the culture and philosophy of India was dreamy and abstract.
It is therefore very necessary that Indians as well as other peoples
should become more and more acquainted with the true characteristics
of the past history of Indian thought and form a correct estimate of its
special features.

But it is not only for the sake of the right understanding of India

viii

that Indian philosophy should be read, or only as a record of the past
thoughts of India. For most of the problems that are still debated in
modern philosophical thought occurred in more or less divergent forms
to the philosophers of India. Their discussions, difficulties and
solutions when properly grasped in connection with the problems of our
own times may throw light on the course of the p