Let us now examine the great problems of all systems of Philosophy relating to God, Nature, individual soul, and knowledge and action, in the light of the five creative energies or the systems of thought based on them, as they are given in the Upanishads.
The Supreme Purusha: We have observed that of the five great systems of Hindu Philosophy the Sankhya alone holds that it has no place for God in its scheme of the universe. According to Vedanta, God is the sole creator of life, one without a second, the creator of Nature or Prakrti itself. Yoga admits the separate existence of Prakrti, but assigns to it a minor part, almost as a spectator of Purusha's work. The Vaisesika makes the two equal or almost equal; while God, according to Nyaya, is like Nature in Yoga, having but a small share in the work of creation, or being a mere witness of Nature's work. We have explained that the origin of this is to be found in the gods of the Vedas, and the same idea is repeated in the Upanishads in more explicit terms.
Brahman: Brahman is the God or supreme Purusha of the Upanishads. We get, indeed, a reference to Prajapati and a number of other gods; but the idea of Brahman is the most comprehensive of all, and includes the different points of view of all systems of Philosophy.
The word Brahman in Sanskrt belongs to the neuter gender, and Brahma is its masculine form. The obvious implication of this is that when we speak of Brahman as supreme creator, we are unable to say whether he is Purusha (masculine) or Prakrti (feminine), and it is for us to find out what he really is. Hence it is that he is said to belong to the neuter gender.
Brahman and Five Creative Energies: We have now to see if there is any authority in the Upanishads for associating Brahman with the five great creative energies of life, from the Soul to Food, on which the corresponding systems of Philosophy are based.
Brahman and the Soul: In connection with the Soul or the Purushic energy of the Heart, we are told that Brahman is seated in the Ether of the Heart, and the five vital airs, or the five gates of the Heart, are the five men of Brahman, the door-keepers of the Svarga-world, and we have explained how Prana or vital air is the vehicle of the Soul, and there are five principal forms of it Prana, Apana, Samana, Udana, and Vyana.
Brahman and Buddhi: In connection with Buddhi, symbolized as the Sun, it is said that the Sun is Brahman, and that he is the person in the Sun, and we are asked to meditate on Buddhi as Brahman.
Brahman and Mind: With regard to the Mind, we are asked to meditate on Mind as Brahman.
Brahman and Ether: Then we are told to meditate on Ether as Brahman.
Brahman and Water, Prakrti, Food: Thus we see that Brahman is associated with the creative energies of all systems of Philosophy, from Vedanta to Nyaya, and only the Sankhya remains, holding that Nature or Prakrti is the sole creator of the universe. But we have explained that Prakrti is symbolized as Water in the Sacred Books of the Hindus; and so we are asked to meditate on Water as Brahman, and Water is said to be one of his forms. Then we have identified Food with Prakrti, and so are told to meditate on Food as Brahman.
Brahman and Systems of Philosophy: We have explained how the idea of Brahman is associated with the creative energies of the different systems of Hindu Philosophy, and we might examine the idea in some further detail. In this connection we have pointed out that the Sankhya has nothing to do with the supreme Purusha, and so we have to confine ourselves to the remaining systems of thought.
Brahman and Sacrifice: In this connection we have observed that we rise from Sankhya to Nyaya and the conception of God through the idea of Sacrifice, which really means creative and selfless action, meant for the benefit of all and then the same idea of Sacrifice leads us to Vedanta. Hence we should find that Brahman is associated with Sacrifice in the Upanishads; and we are told that, "what people call sacrifice is really Brahmacharya" and Brahmacharya literally means, "acting according to Brahma".
Brahman as God of Nyaya: The God of Nyaya, as we have explained, has very little to do with Prakti, and he is often spoken of as a mere witness or spectator of its work. Hence the secondary meaning of Brahmacharya, "acting after the manner of Brahma", is celibacy or absence of creative contact with woman or Prakrti. Thus Brahman, in the idea of Brahmacharya, is the supreme Purusha of Nyaya; and corresponding to this we have the idea of God as actionless, as a mere witness of the phenomena of life. We have already explained that Ether is the creative energy of Nyaya, and it is identified with Brahman.
Brahman as God of the Vaisesika: The creative energy of the Vaisesika is the Mind, and we are asked to meditate on the Mind as Brahman in the Upanishads. Further, as we have observed, the Vaisesika holds that the universe is created by Purusha and Prakrti united together in one; and corresponding to this we have the idea of God "so large as a man and wife together", as the Mind is characterised by Desire, and the Purusha in this system is conceived as an actor equally with Prakrti, we are told that Brahman is he, "from whom all works, all desires, all sweet odours and tastes proceed"; and it is he who, "directs the eye or the ear". Again, he is said to be, "the lord of the lords of the organs (of sense) ... The god who spontaneously covered himself, like a spider, with threads drawn from the first cause (Pradhana or Prakrti)".
Brahman as God of Yoga: We have pointed out that the creative energy of Yoga is Buddhi, and so Brahman is identified with the Sun, the symbol of Buddhi, and we are asked to meditate on Buddhi as Brahman. Further we have explained that Heat or Tapas is the energy of Buddhi or the Sun; and so we are told that "Brahman swells by means of Tapas", and the Supreme creates and dwells in the universe by the power of his thought, which is characteristic of Buddhi. He is conceived as a creator and actor more than Prakrti; he is the cause or creator of the world, "and the source of all beings".
Brahman as God of Vedanta: All philosophical speculations of the ancient Hindus culminate in Vedanta, which holds that the Heart or the Soul is the supreme creative energy of life and Puma the sole creator of the universe; and so the Upanishads describe Brahman in this light at considerable length. He is spoken of as Brahma, assigned to the masculine gender, and described as the maker and preserver of the world, one from whom all this springs forth, including Water or Prakrti, for that too is of Brahman himself. He is the supreme Purusha; he dwells in the Heart, the city of the Heart which contains all desires; and all works, all desires, all sweet odours and tastes proceed from him.
Prakrti and the Sankhya: We have seen how the idea of Brahman as supreme Purusha is associated with all systems of Hindu Philosophy from Vedanta to Nyaya. The Sankhya remains and it holds that Prakrti alone is the creator of the universe and we have authority for this too in the Upanishads. Indeed, as we have pointed out, Brahman himself is identified with Water or Prakrti; and we are told that in the beginning all this was Water. Again, as Prakrti is symbolized as Tamas or Darkness too, it is said that "in the beginning Darkness (Tamas) alone was this (universe). It was in the Highest; and, moved by the Highest, it becomes uneven. Then it becomes Rajas and then Sattva". We see that this corresponds exactly to the Sankhya idea of Prakrti, which is in a state of equilibrium of the Gunas at first, but comes into action when this state of rest is broken by the presence of purusha or the individual soul, or the Highest of the Upanishads.
Prakrti and Vedanta: We have explained that, according to Vedanta, Prakrti is said to have been created by Purusha himself; and so we are told that in the beginning all this was Self, and he created Water (Prakrti).
Prakrti and Other Systems of Philosophy: We have pointed out that in all other systems of Philosophy Yoga, Vaisesika, and Nyaya Purusha and Prakrti are conceived as co-eternal but with varying shares in the creation of life and so we are told that the supreme Creator was so large as a man and wife together. He then made his self to fall into two, and thence arose husband and wife; and this refers to the union of Purusha (husband) and Prakrti (wife) together.
Prakrti as Food: We have explained that Prakrti is identified with Food, understood in its widest sense; and so we are told, "that what is food is Pradhana" (Prakrti), and that "the Purusha is the eater, Prakrti the food". The question of the character of Prakrti in the different systems of Philosophy may, therefore, be examined in the light of the character of Food, and we shall presently consider it in this connection. But, as has been observed, the question of Food is closely related to that of Purusha, the individual soul, or the "eater of food"; and so we shall deal with it after we have examined the problem of the individual soul as discussed in the Upanishads.