Idealism is the foundation of three philosophical schools: the Dialectic, the Atomic, and the Vedanta. The Dialectic school considers the principles of knowledge as entirely distinct from nature; it admits the existence of universal ideas in the human mind; it establishes the syllogistic form as the complete method of reasoning, and finally, it holds as fundamental the duality of intelligence and nature. In this theory, the soul is considered as distinct from Brahm and also from the body. Man can approach Brahm, can unite himself to the universal soul, but can never lose his own individuality.
The Atomic doctrine explains the origin of the world through the combination of eternal, simple atoms. It belongs to Idealism, for the predominance which it gives to ideas over sensation, and for the individuality and consciousness which it recognizes in man.
The Vedanta is the true ideal pantheistic philosophy of India. It considers Brahm in two different states: first, as a pure, simple, abstract, and inert essence; secondly, as an active individuality. Nature in this system is only a special quality or quantity of Brahm, having no actual reality, and he who turns away from ail that is unreal and changeable and contemplates Brahm unceasingly, becomes one with it, and attains liberation.
Mysticism comprehends all doctrines which deny authority to reason, and admit no other principles of knowledge or rule of life than supernatural or direct revelation. To this system belong the doctrines of Patanjali, which teach that man must emancipate himself from metempsychosis through contemplation and ecstasy to be attained by the calm of the senses, by corporeal penance, suspension of breath, and immobility of position. The followers of this school pass their lives in solitude, absorbed in this mystic contemplation. The forests, the deserts, and the environs of the temples are filled with these mystics, who, thus separated from external life, believe themselves the subjects of supernatural illumination and power. The Bhagavad-Gita, already spoken of, is the best exposition of this doctrine.
The Eclectic school comprises all theories which deny the authority of the Vedas, and admit rational principles borrowed both from sensualism and idealism. Among these doctrines Buddhism is the principal.