1. The Philosophy of Nyaya, of which Gotama is said to be the author, is a system of Logic. But this Logic is the path of "deliverance" for the Soul -- not a mere means to deliverance, but in itself actual deliverance, and thus a certain way to bliss. Logic, to wit, leads to true knowledge (the knowledge of the essences of things), and in this precisely consists the emancipation of the Soul.
2. The further development of Nyaya is effected in the Philosophy of Vaiseshika, of which Kanada is reputed the founder. This system may be said to be a Philosophy of Nature, as it deals chiefly with the corporeal world. Vaiseshika advocates the atomic theory. All bodies, according to the disciples of this Philosophy, are formed from homogeneous, minute, indivisible atoms. In dividing bodies we must ultimately reach parts that are no longer divisible; otherwise corporeal substances would contain parts infinite in number, and everything in nature would thus be infinite, and the least equal to the greatest.
3. The combinations of atoms form bodies. "The first combination of two atoms is the simplest. The bipartite elements thus formed combine in threes; the tripartite elements thus arising, in fours; and so on in every increasing number. Only those elements can unite to form a perceptible substance between which there is mutual adaptability. The smallest perceptible magnitude is that of the mote of the sunbeam. This is a combination of the second order, and consists, accordingly, of six atoms. The size of the ultimate atom is, therefore, one-sixth that of the mote of the sunbeam."
4. The combination of atoms to form perceptible bodies is governed, according to Vaiseshika, by a fixed law. The chance combinations of the Greek atomistic doctrines are therefore excluded. Vaiseshika also assumes the existence of a higher force which controls the combinations of the atoms. It will not admit the possibility of spontaneous combinations among them; the action of God must intervene to determine them to union.
5. Vaiseshika furthermore undertakes an explanation of man's nature: there is a soul in man distinct from the body, for he possesses attributes different from the attributes of other things; to wit, intelligence, desire, aversion, will, pleasure, and pain, In the body, on the other hand, are located action and the effort after that which gives pleasure, the organs of sense, and the feeling of sensuous pleasure and pain. Intermediary between soul and body is Ahankara (self-consciousness), which, although united to each individual soul, is yet wholly distinct from it. But everything which in this life is united to the soul is an evil for the soul: "the body is evil, the senses are evil, the objects of sense, the elements, consciousness of the external world, consciousness of self, action, pleasure, and pain."
6. And thus we are again conducted to the term in which all Hindu systems eventually end -- the Deliverance of the Soul. It is the task of the Soul to free itself from the evils of the body, by means of that sacred knowledge in which it contemplates itself as a thing distinct from the body and independent of it. Through this realization of its own essence the Soul rises above the sphere of action, above merit and responsibility, and attains to perfect quietude and bliss.
7. To the systems hitherto set forth we must add three others, with the details of which, however, we are but imperfectly acquainted. They have tbis in common, that they are materialistic in character, and are therefore at variance with the religious doctrines of the Hindus. The first system is that of the Dschainas. In this system a distinction is allowed between the animate and the inanimate, but both, it is contended, are constituted by atoms only. It admits no supramundane existence, and will not acknowledge a Providence. Closely connected with this system is that of the Tscherwakas, which maintains that the corporeal alone is real; that spirit is merely an empty word. Last in order comes the system of the Lokayatikas, an offshoot of the previous school. Here, too, the body is the only reality; spirit is mere nothing. Sensation, consciousness, intelligence, though they do not formally exist in the several elements, exist potentially in them, subject to the condition that these elements combine to form organic bodies. Thought has, therefore, no other cause than a certain definite combination of the elements; it is merely a mode of their co-existence, in the same way as the fermenting together of several substances produces an exciting beverage, which could not be procured from each substance taken separately, nor from all taken together, unless when mixed in the required manner. As long, therefore, as the body exists a fully constituted organism, so long will thought and feeling, joy and suffering, endure; but these cease to exist when the body ceases to be.
8. We may notice that Hindu Philosophy has covered a tolerably wide field during its development. From the loftiest Idealism it descends by many stages to Materialism, and -- if we take the Buddhist doctrines into our reckoning -- even to Nihilism. Many of the notions which we have met with here will confront us again in various guises during the further course of the History of Philosophy. To this extent the Philosophy of India cannot be devoid of special interest for us.