Among the processes which have contributed to form Vishnu and Siva we must reckon the invasions which entered India from the north-west.[336] In Bactria and Sogdiana there met and were combined the art and religious ideas of Greece and Persia, and whatever elements were imported by the Yüeh-chih and other tribes who came from the Chinese frontier. The personalities of Vishnu and Siva need not be ascribed to foreign influence. The ruder invaders took kindly to the worship of Siva, but there is no proof that they introduced it. But Persian and Græco-Bactrian influence favoured the creation of more definite deities, more personal and more pictorial. The gods of the Vedic hymns are vague and indistinct: the Supreme Being of the Upanishads altogether impersonal, but Mithra and Apollo, though divine in their majesty, are human in their persons and in the appeal they make to humanity. The influence of these foreign conceptions and especially of their representation in art is best seen in Indian Buddhism. Hinduism has not so ancient an artistic record and therefore the Græco-Bactrian influence on it is less obvious, for the sculpture of the Gupta period does not seem due to this inspiration. Neither in outward form nor in character do Vishnu and Siva show much more resemblance to Apollo and Mithra than to the Vedic gods. Their exuberant, fantastic shapes, their many heads and arms, are a symbol of their complex and multiple attributes. They are not restricted by the limits of personality but are great polymorphic forces, not to be indicated by the limits of one human shape.[337]
Though alike in their grandeur and multiplicity, Vishnu and Siva are not otherwise similar. In their completely developed forms they represent two ways of looking at the world. The main ideas of the Vaishnavas are human and emotional. The deity saves and loves: he asks for a worship of love. He appears in human incarnations and is known as well or better by these incarnations than in his original form. But in Sivaism the main current of thought is scientific and philosophic rather than emotional.[338] This statement may seem strange if one thinks of the wild rites and legends connected with Siva and his spouse. Nevertheless the fundamental conception of Sivaism, the cosmic force which changes and in changing both destroys and reproduces, is strictly scientific and contrasts with the human, pathetic, loving sentiments of Vishnuism. And scandalous as the worship of the generative principle may become, the potency of this impulse in the world scheme cannot be denied. Agreeably to his character of a force rather than an emotion Siva does not become incarnate[339] as a popular hero and saviour like Râma or Krishna, but he assumes various supernatural forms for special purposes. Both worships, despite their differences, show characteristics which are common to most phases of Indian religion. Both seek for deliverance from transmigration and are penetrated with a sense of the sorrow inherent in human and animal life: both develop or adopt philosophical doctrines which rise high above the level usually attained by popular beliefs, and both have erotic aspects in which they fall below the standard of morality usually professed by important sects whether in Asia or Europe.