His own scheme of causation (often called Paṭićća-samuppādo) occupies an important place in Buddhistic philosophy, as supplementary to, and complementary of, the four truths ([p. 43]). It was thought out before them (see [p. 39]) and is equally revered.
It is on this account that the following celebrated formula is constantly repeated like a short creed, and is found carved on numerous Buddhist monuments:—
‘Conditions (or laws) of existence which proceed from a cause, the cause of these hath the Buddha explained, as also the cessation (or destruction) of these. Of such truths is the Great Ṡramaṇa the teacher[50].’
This was the formula repeated by Assaji to Sāriputta and Moggallāna ([p. 47]), when they wished to join the Buddha and asked for a summary of the spirit (artha), not the letter (vyañjana), of his doctrine (Mahā-v° I. 23. 5). Certainly the sorites-like form of statement in the scheme of causation had charms for Oriental thinkers.
Moreover the Buddha’s method of clothing old truths in a new dress, or—to adopt another metaphor—his plan of putting new wine into old bottles, had in it something very attractive to all Indian minds.
Of what kind, then, was the new dress in which Gautama clothed the great central doctrine of Indian philosophy—the doctrine of metempsychosis, involving the perpetuation of the misery of life?
The Buddha, like all Indians, was by nature a metaphysician. He had great sympathy with the philosophy of the Upanishads. How was it that he disbelieved in the existence of Spirit as distinct from bodily organism? A little consideration will perhaps make clear how he was brought to his own peculiar agnostic view.
Probably before his so-called enlightenment and attainment of true knowledge, he was as firm a believer in the real existence of one Universal Spirit as the most orthodox Brāhman. He had become imbued with Brāhmanical philosophy while sitting at the feet of his two teachers Āḷāra and Uddaka ([p. 29]). At that time there were no definite or formulated philosophical systems, separated from each other by sharp lines. But the Sāṅkhya, Yoga, and Vedānta systems were assuming shape, and the doctrines they embodied had been foreshadowed in the Upanishads, and were orally current.
In short, it had been repeatedly stated in the Upanishads, that nothing really existed but the one universally present impersonal Spirit, and that the whole visible world was really to be identified with that Spirit.
Then it followed as an article of faith that man’s spirit, deluded into a temporary false idea of separate independent personal existence by the illusion of ignorance, was also identical with that One Spirit, and ultimately to be re-absorbed into it.