All the Darsanas have as a common principle this idea of Karma with the attendant doctrines that rebirth is a consequence of action and that salvation is an escape from rebirth.  They all treat more or less of the sources and standards of knowledge, and all recognize the Veda as one of them.  There is not much more that can be said of them all in common, for the Vedanta ignores matter and the Sankhya ignores God, but they all share a conviction which presents difficulties to Europeans.  It is that the state in which the mind ceases to think discursively and is concentrated on itself is not only desirable but the summum bonum.  The European is inclined to say that such a state is distinguished from non-existence only by not being permanent.  But the Hindu will have none of this.  He holds that mind and thought are material though composed of the subtlest matter, and that when thought ceases, the immaterial soul (purusha or atman) far from being practically non-existent is more truly existent than before and enjoys untroubled its own existence and its own nature.

Of the three most important systems, the Sankhya, Yoga and Vedanta, the first and last are on most points opposed:  both are ancient, but perhaps the products of different intellectual centres.  In one sense the Yoga may be described as a theistic modification of the Sankhya:  from another and perhaps juster point of view it appears rather as a very ancient science of asceticism and contemplation, susceptible of combination with various metaphysical theories.

2

We may consider first of all the Sankhya.[740] Tradition ascribes its invention to Kapila, but he is a mere name unconnected with any date or other circumstance.  It is probable that the principal ideas of the Sankhya germinated several centuries before our era but we have no evidence whatever as to when they were first formulated in Sutras.  The name was current as the designation of a philosophical system fairly early[741] but the accepted text-books are all late.  The most respected is the Sankhya-pravacana,[742] attributed to Kapila but generally assigned by European critics to the fourteenth century A.D.  Considerably more ancient, but still clearly a metrical epitome of a system already existing, is the Sankhya-Karika, a poem of seventy verses which was translated into Chinese about 560 A.D. and may be a few centuries older.  Max Mueller regarded the Tattva-samasa, a short tract consisting chiefly of an enumeration of topics, as the most ancient Sankhya formulary, but the opinion of scholars as to its age is not unanimous.  The name Sankhya is best interpreted as signifying enumeration in allusion to the predilection of the school for numbered lists, a predilection equally noticeable in early Buddhism.