One may divide the philosophical development of India into three stages: pre-logical up to the beginning of the Christian era, logical up to the Muhammadan domination of India, A.D. 1000 or 1100, ultra-logical, and A.D. 1100-1700.
The contribution of the first period is to be found in the philosophical hymns of the Vedas, in the more mature Upanishads, in the Gita, which is something like a metrical commentary on the Upanishads, working out their ideals in their practical bearing to life; and in the rise and growth of Buddhism and the Sankhya and the Vaiseshika philosophy.
From about the beginning of the first or second century B.C. we have the various systems of Indian philosophy, the Yoga-sutras, the Sankhya treatises, the Mimamsa-sutras, the Brahma- sutras, and the Nyaya-siitras, and their numerous commentaries and sub- commentaries.
In the third period we have keen discussions and dialectics of an extremely subtle character such as had never developed in Europe at that time, and which are in part so difficult that few Occidental scholars have been able to master them.
In the philosophical hymns of the Vedas we come across men who were weary of seeking mere economic welfare through religious rituals of a magical character. They wished to know something greater than their ordinary religion and sought to delve into the mystery of the Universe-the highest and the greatest truth.
They formed the conception of a being who is the depository and the source of all powers and forces of nature, from whom nature with its manifold living creatures has emanated and by whom it is sustained and maintained. In spite of all the diversity in the world there is one fundamental reality in which all duality ceases.
The highest truth is thus the highest being, who is both immanent in the world and transcendent. He holds the world within him and yet does not exhaust himself in the world. The ordinary polytheism and henotheism of Vedic worship thus slowly pass away, sometimes into monotheism and sometimes into pantheism; and in this way some of the Vedic hymns declare the spirituality of the world and denounce the common- sense view of things.
This view is developed in the Upanishads, which may be regarded as a continuation of the philosophical hymns of the Rig-Veda and the Atharva-Veda. In the Kena Upanishad we are fold the story of how all the presiding gods of the powers of nature, such as fire and wind, tried their best to compete with Brahman, as this ultimate being was called, but the fire could not burn a piece of straw and the wind could not blow it away against the wishes of Brahman, for they all derived their powers from him.
We have a vivid description in the Mundaka of how the world has emanated from Brahman, like sparks from the fire or like the spider’s web from the spider. But the Upanishads advance the thought a little further. They do not merely speculate on the nature of Brahman externally as both the immanent and the transcendent cause of the world, but they also try to demonstrate its reality in experience.
Neither the Upanishads, nor the philosophical hymns of the Vedas, give us any reasons in demonstration of their conception of the ultimate being. They do not raise any questions, or give any premises from which they drew their conclusions.
Their opinions are only dogmatically asserted with the forceful faith of a man who is sure of his own belief. But, after all, it is only a belief, and not a reasoned statement, and there naturally raises the question as to its validity.