Such is the Sānkhya system; but it would be dangerous to affirm that the whole came from Kapila; for no treatise written by him has come down. The earliest systematic manual of the philosophy extant to-day is the Sānkhya-Kārikā of Isvara-Krishna, which dates from the early Christian centuries.[[21]]

E. Shortly after the Sānkhya system, and in close dependence upon it, there appeared Buddhism and Jainism; but as these great religions exercised no very definite influence on the main stream of Indian thought for several centuries, we shall not linger over them.

F. We notice next the second great group of Upanishads, the Katha, Isā, Svetāsvatara, Mundaka, Mahānārāyana,[[22]] which are all written in verse. That this group is later than the great prose Upanishads is abundantly clear from the changed form as well as from the more developed matter. “As contrasted with the five above-mentioned Upanishads with their awkward Brāhmana style and their allegorical interpretations of the ritual, the Katha Upanishad belongs to a very different period, a time in which men began to coin the gold of Upanishad thought into separate metrical aphorisms, and to arrange them together in a more or less loose connection.”[[23]] Further signs of their belonging to another stage of thought are their references, more or less clear, to the Sānkhya and Yoga philosophies,[[24]] and their tendency to adopt the doctrine of Grace,[[25]] i.e., that salvation is not a fruit of true knowledge, but a gift of God. The idea of Bhakti, which became afterwards so popular, appears in this group of Upanishads only once.[[26]] Here also for the first time in Sanskrit literature the word Sānkhya occurs as the name of a system.[[27]]

But while these five metrical treatises are clearly later than the prose Upanishads, scholars are not agreed on the question of their relation to the great systems. Some[[28]] hold that the Katha is earlier, others[[29]] that it is later, than Buddhism; Weber[[30]] believes that the Svetāsvatara, Mundaka, and Mahānārāyana depend not only on Kapila’s system, but also on the Yoga Sūtras of Patanjali (see below), while others[[31]] believe that in these Upanishads we have scattered pieces of teaching which were later systematized. But whatever be the truth on these points, it is clear that these five are posterior to the first group, that their relative age is Katha, Isā, Svetāsvatara, Mundaka and Mahānārāyana,[[32]] and that this last belongs to quite a late date.[[33]] Along with these verse Upanishads we may take three prose works, which are manifestly still later,[[34]] the Prasna, Maitrāyanīya and Māndūkya.

G. Several centuries after the Sānkhya there appeared the Yoga philosophy, the text-book of which is the Yoga Sūtras. According to Indian tradition the founder of the school and the author of the Sūtras was Patanjali,[[35]] the well-known scholar who wrote the Mahābhāshya on Pānini’s grammar. He accepts the metaphysics of the Sānkhya system, but postulates the existence of a personal god, and urges the value of Yoga practices for the attainment of Kaivalya, that isolation of the soul from matter, which, according to Kapila, is true salvation. Thus not one of the three main elements of his system is original; for Yoga practices have existed from a very early date in India. Yet his system is sufficiently marked off from others, first by his combination of Yoga practices with Sānkhya principles and a theistic theology, and, secondly, by his systematic treatment of Yoga methods.[[36]]

H. Later still than the Yoga philosophy is the systematic statement of the Vedānta point of view by Bādarāyana in his Sūtras, which are known either as Brahma-sūtras, Sārīraka-sūtras or Vedānta-sūtras.[[37]]

I. We next notice the latest development of Upanishad teaching, namely, that found in the Upanishads of the Atharvaveda. With the exception of three, namely, the Mundaka, Prasna and Māndūkya Upanishads, which we have already noticed, they are all very late.[[38]] They fall into four great groups, according as they teach (a) pure Vedantism, (b) Yoga practices, (c) the life of the Sannyāsin, or (d) Sectarianism.[[39]] For our purpose the last of the four is of the most importance. “These sectarian treatises interpret the popular gods Siva (under various names, such as Isāna, Mahesvara, Mahādeva) and Vishnu (as Nārāyana and Nrishinha) as personifications of the Atman. The different Avatārs of Vishnu are here regarded as human manifestations of the Atman.”[[40]] Let readers note that the doctrine of Avatārs is quite unknown in the Vedas, the Brāhmanas, the early Upanishads and the Sūtras.[[41]] We may also note that in groups (a) and (b) we find what is not found in earlier Upanishads, namely, the phrase Sānkhya-Yoga used as the name of a system.[[42]] Here also the doctrines of Grace and Bhakti, the beginnings of which we found in the verse Upanishads, are regularly taught.

J. The last development that we need mention is the teaching of the Mahābhārata and Manu. We take them together, not only because each of them is the final product of long centuries of growth and compilation, but because they are so closely related to each other in origin, that it is hardly possible to take them separately.[[43]] In the first book of the Mahābhārata we are told that the poem originally consisted of only 8,800 slokas, and that at a later date the number was 24,000. The complete work now contains over 100,000 slokas.[[44]] We need not here enquire when the simple heroic lays were composed, which lie at the basis of the great composition as it has come down to us; nor need we stay to decide at what period it finally reached its present labyrinthine structure and immense dimensions.[[45]] It is sufficient for our purpose to notice that scientific investigations have laid bare four stages in the formation of the Epic:—(a) early heroic songs, strung together into some kind of unity: this is the stage recognised in Book I, when the poem had only 8,800 slokas, and is in all probability the point at which it is referred to by Asvalāyana; (b) a Mahābhārata story with Pandu heroes, and Krishna as a demi-god: this is the form in which it had 24,000 slokas, and is the stage of the poem referred to by Pānini; (c) the Epic re-cast, with Krishna as All-god, and a great deal of didactic matter added; (d) later interpolations.[[46]] Scholars are able to fix, within certain limits, the dates of these various stages. We need not attempt to be so precise: for us it is enough that the representation of Krishna as the Atman belongs to the third stage of the growth of the Epic. Parallel with this third stage is the final redaction of Manu.[[47]] The philosophic standpoint of these two great works is practically the same, being now the Sānkhya-Yoga, now a mixture of Sānkhya, Yoga and Vedantic elements.[[48]]

But the main thing to notice is that in these books we are already in modern Hinduism. Turning from the Vedas to them we find ourselves in an altogether new world. There are many new gods; most of the old divinities have fallen to subordinate places. New customs, new names and ideas are found everywhere. The language too has changed: new words, new expressions and new forms occur in plenty; old words occur in new senses; while many others have disappeared.[[49]]