plausibility; and each could find some phenomena which countenanced his own peculiar view. As far as we can judge, Leukippus and Demokritus greatly surpassed the others, partly in the pains which they took to elaborate their theory, partly in the number of facts which they brought into consistency with it. The loss of the voluminous writings of Demokritus is deeply to be regretted.[8] [Footnote 5: Karsten observes, in his account of the philosophy of Parmenides (sect, 23, p. 241):-- "Primum mundi descriptionem consideremus. Argumentum illustre et magnificum, cujus quanto major erat veterum in contemplando admiratio, tanto minor ferè in observando diligentia fuit. Quippe universi _ornatum et pulcritudinem admirati_, ejus _naturam partiumque ordinem non sensu assequi_ studuerunt, sed _mente informarunt ad eam pulcri perfectique speciem quæ in ipsorum animis_ insideret: sic ut Aristoteles ait, non sua cogitata suasque notiones ad mundi naturam, sed hanc illa accommodantes. Hujusmodi quoque fuit Parmenidea ratio."] [Footnote 6: Xenophon, Memor. i. 1, 13-14.] [Footnote 7: Plato, Legg. ii. 656-657.] [Footnote 8: About the style of Demokritus, see Cicero De Orat. i. 11. Orator. c. 20.] [Side-note: All these theories were found in circulation by Sokrates, Zeno, Plato, and the dialecticians. Importance of the scrutiny of negative Dialectic.] In studying the writings of Plato and Aristotle, we must recollect that they found all these theories pre-existent or contemporaneous. We are not to imagine that they were the first who turned an enquiring eye on Nature. So far is this from being the case that Aristotle is, as it were, oppressed both by the multitude and by the discordance of his predecessors, whom he cites, with a sort of indulgent consciousness of superiority, as "the ancients" ([Greek: oi( a)rchai=oi]).[9] The dialectic activity, inaugurated by Sokrates and Zeno, lowered the estimation of these cosmical theories in more ways than one: first, by the new topics of man and society, which Sokrates put in the foreground for discussion, and treated as the only topics worthy of discussion: next, by the great acuteness which each of them displayed in the employment of the negative weapons, and in bringing to view the weak part of an opponent's case. When we look at the number of these early theories, and the great need which all of them had to be sifted and scrutinised, we shall recognise the value of negative procedure under such circumstances, whether the negationist had or had not any better affirmative theory of his own. Sokrates, moreover, not only turned the subject-matter of discussion from physics to ethics, but also brought into conscious review the _method_ of philosophising: which was afterwards still farther considered and illustrated by Plato. General and abstract terms and their meaning, stood out as the capital problems of philosophical research, and as the governing agents of the human mind during the process: in Plato