f nature. Any natural force might be designated psyche: thus Thales uses this term for the attractive force of the magnet, and similar language is quoted even from Anaxagoras and Democritus. With this we may compare the "mind-stuff" theory and Pan-psychism of certain modern scientists. Other philosophers again described the soul's nature in terms of substance. Anaximander gives it an aeriform constitution, Heraclitus describes it as a fire. The fundamental thought is the same. The cosmic ether or fire is the subtlest of the elements, the nourishing flame which imparts heat, life, sense, and intelligence to all things in their several degrees and kinds. The Pythagoreans taught that the soul is a harmony, its essence consisting in those perfect mathematical ratios which are the law of the universe and the music of the heavenly spheres. With this doctrine was combined, according to Cicero, the belief in a universal world-spirit, from which all particular souls are derived. All these early theories were cosmological rather than psychological in character. Theology, physics, and mental science were not as yet distinguished. It is only with the rise of dialectic and the growing recognition of the problem of knowledge that a genuinely psychological theory became possible. In Plato the two standpoints, the cosmological and the epistemological, are found combined. Thus in the "Timaeus" (p. 30) we find an account derived from Pythagorean sources of the origin of the soul. First the world-soul is created according to the laws of mathematical symmetry and musical concord. It is composed of two elements, one an element of "sameness" (tauton), corresponding to the universal and intelligible order of truth, and the other an element of distinction or "otherness" (thateron), corresponding to the world of sensible and particular existences. The individual human soul is constructed on the same plan. Sometimes, as in the "Phaedrus", Plato teaches the doctr...
