The Historians' History of the World 04

Equally great is the influence of Parmenides, the Kant of the ancient world. Descended from an Ionian family of rank which had taken refuge at Elea in Italy at the time of the occupation of Phocæa (560), he carries on the tradition of the philosophic poetry of Xenophanes, whose Pantheistic Monism he defends in acute polemics against the “two-headed” Heraclitus. Being—one, eternal, indivisible, immutable, unchangeable—is alone intellectually conceivable. All beside—multiplicity, divisibility, mobility, variability—is logically inconceivable and therefore non-existent. Reason (logos) is consequently the measure of all things. His system is abstract and logical to absurdity, but his postulate that this monistic Being must be bounded like a globe that is equally closed in all directions reminds us that we are still in the age of physics. In him the scepticism of Xenophanes hardens into the assertion that everything which contravenes his logical postulate of the Sole Existent—such as multiplicity, colour, motion, becoming and ceasing to be—is mere illusion.

The logical and sceptical bias of the Eleatics is surpassed by the hair-splitting dialectics of Zeno, whose evidences against motion and multiplicity still perplex the thinkers of to-day. On the one hand this precise manipulation of the laws of thought which represents the culminating point of Ionic rationalism redeems the negative Sophism which was beginning to deny the actuality and perceptibility of things themselves (Protagoras, Gorgias), while on the other hand the positive result of this strict definition of the highest conception of Being was to call forth a series of systems which came into existence almost simultaneously, though subject in part to reciprocal influence, a little before the middle of the fifth century. Such was the Doctrine of the Elements taught by Empedocles of Agrigentum, who once more found the idea of the imperishable principle in the fourfold root of Being (the four elements) and brought about the Heraclitic alternation of the external world by the introduction of the two polar forces of love and hate.

The idea of the Element in endless subdivision (which could not be evaded in the world-process of Empedocles) and in endless diversity of quality was strongly brought out by Anaxagoras the Ionian in his homoiomere. To this chaos he opposed the thinking and directing reason (nous) as a distinct existence, thus definitely breaking with the idea of a hylozoistic union of matter and force, which had already threatened to go to pieces in the systems of Heraclitus and Parmenides, and setting forth the positive dualism of God and the world, i.e., of the Universal Reason working towards predetermined ends and the blind chaotic mass of matter.

More important than either of these two is Leucippus of Miletus, the founder of the atomistic theory, who, as Theophrastus rightly asserts, starts from the position of Parmenides. For he finds the homogeneous, eternal, complete, and indivisible, unchangeable Existence, to which no quality can be ascribed, in the “atom,” and solves the difficulties which arose for the Eleatics out of the idea of multiplicity by assuming the existence of an infinite number of such units. Hence results a mechanical interpretation of nature, which proved of all ancient systems the most serviceable for the elucidation of physical and physiological facts. By explaining sensory impressions by mechanical transmission from object to subject, he propounds the first theory of sensory perception, and since, in consequence of this assumption, he regards such qualities as colour, taste, etc., as subjective sensory impressions to which atoms in different arrangements correspond objectively, he lays the foundation of a distinction between primary and secondary qualities which has not been rightly appreciated until modern days.

Generally speaking, the value of the Leucippic theory has only been recognised since the Renaissance. For although Democritus of Abdera extended his master’s admirable system to fresh departments of knowledge, established it more firmly by combating the sensualism of Protagoras and other theories arising from a misunderstanding of Leucippus, and, above all, brought it to a high pitch of mathematical and notional exactitude, yet the atomistic school which continued to exist at Abdera till into the fourth century has passed almost utterly out of mind. Plato ignored it, although he adopted many of its theories indirectly; Aristotle alone made use of it, though not as regards the main points of its teachings; and Epicurus, who borrowed from it almost the whole of his theoretical science, by this very absorption played the chief part in the destruction of the Abderite writings, the greatest loss that science has ever suffered.