Oriental scholars tell us that, 500 years before Christ, in India, China, Greece, and Persia men began to formulate philosophical systems of religious belief, and to elaborate scientific ideas of the world in which they lived. Williams considers the _Vais’eshika_ system of philosophy the most interesting of all the systems, from the parallels it offers to European philosophical ideas. This system goes more correctly than the others into the qualities of all substances. It is therefore more scientific, as we should say. It is most interesting to discover how nearly the doctrine of the atoms approaches our Western teaching. The following is Professor Williams’ account of these views:— “First, then, as to the formation of the world, this is supposed to be effected by the aggregation of _Anus_, or ‘Atoms.’ These are innumerable and eternal, and are eternally aggregated, disintegrated, and re-integrated by the power of Adrishta. According to the Kanādas Sūtras, an atom is ‘something existing, having no cause, eternal.’ They are, moreover, described as less than the least, invisible, intangible, indivisible, imperceptible by the senses, and as having each of them a _Vis’esha_ or eternal essence of its own. The combination of these atoms is first into an aggregate of two, called _Duy-anuka_. Three of them, again, are supposed to combine into a _Trasa-renu_, which, like a mote in a sunbeam, has just magnitude enough to be perceptible.”[226] In the Sānkhya philosophy we find something very like Darwinism. “There cannot be the production of something out of nothing; that which is not cannot be developed into that which is. The production of what does not already exist (potentially) is impossible, like a horn on a man; because there must of necessity be a material out of which a product is developed; and because everything cannot occur everywhere at all times; and because anything possible must be produced from something competent to produce it.” (_Aphorisms_, i. 78, 114-117).[227] The _Upa-Vedas_, or secondary _Vedas_, treat of various sciences, one of which, _Ayur-Veda_, is the “science of life,” or medicine. By some this is considered to belong to the _Atharva-Veda_; by others to the _Rig-Veda_. By _Ayur-Veda_ we are to understand something derived immediately from the gods. The supplementary revelation known as _Upa-Vedas_ dates about 350 B.C., and there we find Brahmanical medicine already developing.[228] “Of all ancient nations,” says Elphinstone, “the Egyptians are the one whom the Hindus seem most to have resembled.”[229]