They were linked together in pairs, as complementing one another or otherwise showing close relations. The three pairs were: (i) Sankhya and (ii) Yoga; (iii) Nyaya and (iv) Vaise- shika; and (v) Mimamsa and (vi) Vedanta or Uttara-Mlmamsa
The Sankhya is probably the earliest Indian attempt at systematic philosophy. Its foundation is attributed to Kapila, who is said to have written the original textbook of the school, the Shashti-tantra in sixty chapters. This work is now lost, and we know only the names of those chapters.
We find elements of Sankhya even in the earliest Upanishads, and we have reason to believe that the system was probably not originally written, but underwent a course of development at different stages and under different influences; though it is possible that at some particular stage Kapila may have contributed so much towards its systematization as to be generally regarded as the original expounder of the system. It is generally accepted that the Sankhya has two principal schools, the atheistic and the theistic. The theistic Sankhya is now associated with Patanjali and is otherwise called the Yoga system.
The oldest surviving text of the atheistic or non-theistic School of Sankhya in its generally accepted form is a compendium of Isvara Krishna (third century a.d.). Patanjali is supposed to have flourished somewhere about the middle of the second century b.c. The Sankhya and Yoga, in their various forms, have profoundly influenced Hindu culture and religion in all their varied aspects.
According to Sankhya the word prakriti means the original substance, which consists of three classes of neutral entities called gunas-Sattva, representing truth and virtue, Rajas, present in all that is active, fiery, or aggressive, and Tamas, the principle of darkness, dullness, and inactivity.
These are continually associating with one another for the fullest expression of their inner potentialities. They form themselves into groups, and not only are the inner constituents of each of the groups working in union with one another for the manifestation of the groups as wholes, but the wholes themselves are also working in union with one another for the self-expression of the individual whole and of the community of wholes for the manifestation of more and more developed forms.
Causation is thus viewed as the actualization of the potentials. The order of all cosmic operations is deduced from the inherent inner order and relations of the neutral reals. Relations are conceived as the functions of these reals, with which they are metaphysically identical. Prakriti is regarded as the hypothetical state of the pure potential conditions of these reals.
It is supposed that this pure potential state breaks up into a state which may be regarded as the stuff of cosmic mind. This partly individuates itself as individual minds, and partly develops itself into space, from that into potential matter, and later on into actual gross matter as atoms.
The individuated minds evolve out of themselves the various sensory and conative functions and the synthetic and analytic functions called manas. They also reveal themselves in the psychical planes or personalities of individuals.
It is evident that the complexes formed from the neutral reals derive their meaning and functioning through a reference to the other or the others, for the manifestation of which they are co-operating together. This other- reference of the reals (gunas) is their inherent teleology. But such other- references must have a limit, if an infinite regression is to be avoided.
In a general manner it may be said that the two broad groups, the psychical and the physical, are working together in mutual reference. It is therefore assumed that there is an unrelational element, called purusha, a pure consciousness which presides over every individuated mind. By reference to this the non - conscious psychic phenomena attain their final meaning as conscious phenomena.
The whole history of conscious phenomena attains its last metaphysical purpose in self-annulment, by an ultimate retroversion of reference from purusha towards the ultimate principle of consciousness, by which the financial other-reference to the purusha ceases.
There must be a stage in which the positive other-references end themselves in self-reference, whereby the ultimate bond of the psychic manifestation or the personality with the purusha will cease. This cessation in the history of any individual psychic plane marks, its culmination and is regarded as a final metaphysical liberation of the purusha associated with that individual psychic plane. There are as many purushas as there are psychic planes. The purusha is regarded as the principle of consciousness unrelated to its fellow purushas and also to any of the complexes of the neutral reals.
It has already been said that space is derived as a modification of the reals. Time is to be regarded as having a transcendental and a phenomenal aspect. Under the former, time is identical with the movement inherent in the guna reals and as such it is even prior to space.
In the latter aspect, that is time as measurable, and as before and after, it is mental construction in which the ultimate unit of measure is regarded as the time taken by an atom to traverse its own dimension of space.
Since all conceivable objects in the world are products of the guna reals, and since there is no other agent, the guna reals hold within themselves in a potential manner all things of the world, which are manifested first in the emergent categories of cosmic personality, ego, the eleven senses, five kinds of potential matter, and five kinds of actual matter. These together form the twenty-five categories from the enumeration of which the Sankhya system is supposed to have drawn its name, meaning numeration or counting.