and boldness, referring all authority to the testimony of the senses or experience, and reserving to the powers of reason the privilege of attaining true knowledge.

In a poem of his which yet remains, and which, like all other philosophical works of the time, bears for its title, "On Nature," the first part treats of " truth," or the " unity of that which is."

In this he asserts, that "that which is, is," that that "which is nought, cannot be conceived, -that speech, thought, and being compose all that is in reality, that men, blinded by the evidence of their senses, confound that which is with that which is not. There are many causes for believing that that which is never began and cannot cease to be. It is entire, it is one, it is immutable and infinite. For else, whence was it derived, from what source can it borrow the nourishment for its growth? Surely not from that which is nought. For who can conceive a power which can make any thing which is not, arise out of a state of non-existence, and appear at a certain moment, neither sooner nor later, ready fashioned and complete? Being must then be eternal, or not be at all: for this maxim is irrefragable, Nothing can of itself arise out of nothing.' Founded in itself, the universal being rests on itself, and exists permanently. Thought and the object of thought are one; for there can be no thought without a reality on which it seizes. Those who speak of beginning and end, of change of place and transformation, yield to the suggestions of human prejudice, and employ words destitute of meaning. The form of the whole is perfect: it resembles the sphere, whose centre is equally distant from every part of the surface. There is no void to interrupt the continuity of that which is real."

The second portion of the work is entitled, "Opinion:" it is a picture of the sensible world, of material nature, a suite of hypotheses on its principles and laws. It assigns two opposing principles to the universe the one a subtile and ethereal fire; the other, night.

Such were the notions of Parmenides, who is usually considered the founder of idealism among the Greeks.

Two other philosophers of the school of Elea, opposing all doctrines founded on experience, avowed themselves partisans of the absolute and intelligible unity, Melissus and Zeno. The former confines himself to a commentary on the system of Parmenides; the latter undertook its defence from the attacks made upon it. Melissus almost only reproduces the proposition of his predecessor: he asserts that something must exist, for we cannot attribute a quality to a thing without conceiving it real. But that which is real cannot end; and is infinite, not in space but in duration: it fills up the whole of time and is always like to itself. That space and void are equally impossible. Since what is, is indivisible and composed of parts, he concludes that it cannot admit of form nor dimensions, a consequence of the principle of Xenophanes and Parmenides, which, however, they had not themselves deduced.

A doctrine which attacked so boldly the general and constant testimony of experience, and the evidence of the senses, could not be published without meeting the most energetic contradictions. The instincts of nature and internal consciousness were the opponents set

up against this novel system, and thus arose the first regular controversy that is met with in the history of philosophy.

Zeno was the champion who rose up to defend the difficult position of the Eleatics. In order to perform this duty in the most effective manner, he undertook to attack the enemy on his own ground. He pretended to derive from all phenomena which were perceptible to the senses, and especially from those of motion, a series of paradoxes, which he very artfully put together. Each side seemed more anxious to destroy the system of the other than to defend that which themselves professed. This seems to be the course of human nature; for it is more easy to refute the arguments of another than to justify the truth of your own. The following are examples of Zeno's subtle attacks. 66 Every body," said he, "occupies a space equal to itself. It is every instant at rest. But, if it moves, it must move every instant, or it moves and is at rest at the same time." Again, "If space is a real thing, it must be somewhere for all that exists must be in some place: therefore this space requires some previous space, and so on to eternity." Zeno endeavoured to prove that absolute unity could not be found in sensible objects, and employed a most ingenious argument derived from the infinite divisibility of matter. "For," says he, "if you arrive at unity in sensible objects, you will come to a mathematical point, which has no real existence."

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By this mode of controversy Zeno was led to the invention of logic, which at first was considered rather as the art of disputation than as a direct method of arriving at the truth, which character, indeed, it has constantly preserved, and is made use of now as it was then as a weapon for combat, not as an instrument for investigation. In drawing up the first sketch of this art, Zeno gave it three principal branches: the art of deducing consequences; the art of conversing; the art of discussing.

The first of these branches consists in establishing, by way of supposition, the two opposite propositions, and then, in attacking the corrollaries which result from each, considering it as true. This method Zeno honoured with the name of dianoetic, which implies that it contains the art of thinking well.

The second method was styled the dialectic, and comprised the art of putting questions and making answers, for which purpose Zeno drew up a set of rules, which had so great a success that the didactic form of communicating knowledge, hitherto adopted, was no longer made use of.

The third division, or the art of discussion, which has been confounded with the second, consisted of artificial subtleties, the nature of which can be best understood by attending to the following example attributed to Zeno:-" Achilles, who was distinguished for his swiftness, could never catch a tortoise. For a body in motion must pass over the given space, and over half the given space. space is infinitely divisible, like time. Achilles must run over an infinite space before he could come up with the tortoise."

But

We perceive that Xenophon, Parmenides, Melissus, and Zeno, form a group by themselves in the annals of philosophy. They all agreed in founding their philosophy on the idea of a real absolute and

unique substance, and in demonstrating that the principle "nothing comes of nothing" could not be applied to experience and observation without giving rise to manifest contradictions. Xenophanes identified God, the universe, reality, in the unity of the being, attributing to it omnipotence and intelligence. Parmenides admitted the same idea, but applied rather to the universe than the Deity, to the existence than the cause. Melissus perceived this consequence, and Zeno developed its bearings, namely, that the simplicity of the sole being did not allow of its occupying space. Thus, the more determinate this idea became the more rigorous the deductions from it; it by degrees lost every attribute, and, from abstraction to abstraction, at last vanished as a conception devoid of sense and value. These philosophers form the heads of the metaphysical school. We will now turn our attention to Heraclitus. There remain to us but some faint outlines of his opinions, which, however, carry with them the evidence of a grand character and sublime conception.

He seems to have directed his attention peculiarly to the investigation of the laws of the universe. He affirms "that all nature is governed by immutable laws: the very phenomena which appear most discordant arise out of and contribute to the harmony of the whole. Thus the different beings, whatever may be their variety, united in the same place, form one whole and tend to the same end.” Heraclitus thus avoided the rock on which Xenophanes split, comprehending how unity and diversity may be assimilated, and penetrating the principle on which the great problem binges. Destiny, according to Heraclitus, is only this great harmony, or rather its principle; not a blind power, but the general law imposed upon the universe by the supreme Intelligence.

"All things are subject to a continual change; the torrent rolls on incessantly, but in the midst of these revolutions nature moves with an equable step. The operations of attraction and repulsion combine and separate the indivisible and elementary particles (nyμata); an endless and universal activity sets these great springs, condensa tion and evaporation, in motion; we cannot then so properly say that things are in existence as that they pass through an existence. This indefatigable source of reproduction is, according to his theory, fire, which causes expansion, penetrates all recesses, dissolves, volatilizes, and transforms. Not fire, such as it appears to our senses, but an ethereal exhalation or vapour-an immaterial, intelligent, luminous, and igneous power: in short, a soul.

Heraclitus explains more distinctly than the other Eleatic philosophers the distinction between the two worlds: the one invisible and only accessible to the reason, the other physical and perceptible to the senses. He says that the human soul, inasmuch as it is endowed with reason, is an emanation of the universal soul,-that it is united to another animated substance, which we have in common with other animals of a different nature, and material. He asserted that the same could not be conceived but by the same, which opinion led him to reject the evidence of the senses and trust entirely to reason. He, however, admitted the senses as open channels by which we might

receive the aspirations of the divine reason. He gave great authority to the evidence of common sense. "For," said he, "the judgments on which all men agree bear strong internal testimony of truth. The ray which enlightens them all at once is but an emanation of the divine reason spread through all thinking beings."

Heraclitus defined virtue as the empire which men exercise over their passions. His morality was a corollary of his principal theory, from which he deduced this excellent maxim, "That human laws derive their authority from that divine law which governs all at its will, and holds all in subjection."

Hippocrates has been by some supposed a disciple of Heraclitus. The father of medicine deserves a high rank among philosophers; in all the branches of medical science he set an admirable example of the method in which all other sciences should be pursued. He collated and compared the results of his own observation, and all others of which he could obtain a knowledge, and taught that true research consisted in associating reason with experience. His system is contained in a few words: "All rules must be drawn from practice, not anterior reasoning, but from experience directed by reason. The judgment is a sort of memory which collects and puts in order all the impressions it has received from the senses; for, before thought is produced, the senses have experienced all that which furnishes it, and through them are materials conveyed to the understanding."

However, all the philosophers of the school of Elea did not follow this course of beginning with absolute rationality and ending in doubt.

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Leucippus endeavoured to stop this war among the partisans of reason and of experience, and he thus endeavoured to reconcile their conflicting doctrines: Experience shows us numerous and distinct objects, motions and changes, productions and destructions; reason seems to require unity, infinity, and permanence." Leucippus distinguished the things composed from the elements of which they were formed. These elements possessed a few peculiar properties, such as motion and form, were simple and indivisible, and infinite in number. Thus the hypotheses of reason were satisfied; the combinations of these particles were continually varying; their junction and separation caused the generation and dissolution of things. Thus the senses were not outraged. This was the hypothesis by which Leucippus considered he had solved the fundamental problem of the Eleatics. He did not differ much in his system from those of his metaphysical predecessors; but Democritus advanced still nearer to them. He pretended to prove the existence of those atoms à priori by the aid of the principle "nothing comes of nothing." He supposed that time had no beginning. "We cannot," says he, "enquire why things exist, since they have always existed. We can only enquire, what reasons we have for supposing that they exist at all." His theory on sensations is curious, and is the first which is to be met with in history.

"The soul, the common principle of motion and thought, is material and composed of atoms of fire. It is entirely passive in its intellectual

functions, and all its knowledge is acquired from without; but objects act upon it in two very different manners: bodies, by their violent action on its organs, transmit to it divers impressions; certain media, such as air and water, are necessary for this communication. These impressions, colours, smells, sounds, &c., do not correspond to any real object: they even exist after the body itself has disappeared by the effect of a vibration which is prolonged in our organs. Real objects which are invisible to our senses, namely, atoms, act directly on the understanding, and transmit to it in their passage images of themselves, which serve to retrace them on the spirit.

In another place he draws a line between the senses and reason. "The first," he says, "are imperfect, obscure, and deceptive: the second all fit for the impress of truth, for atoms, which are the only real objects, are not perceptible to the senses." We here see that Democritus falls back upon the rationalism of the Eleatic metaphy

sicians.

Empedocles displays in his philosophy a mixture of the tenets of all the schools which preceded him. To the three elements of the Ionians he added the earth. Following the example of the Eleatics, he considered these elements as composite matters. The unity of the Pythagorean monad was the first principle in his eyes. He considered the exercise of thought as a function of the physical organs, subjected to all their laws and all their accidents. While he materialized existence, he filled the air with spirits and genii. principal merit was the having carried to greater extent the analysis of Democritus of sensations.

His

Zeno, by defending a bad cause with great skill, attacking the instincts of common sense with much art, and designedly multiplying paradoxes, showed by his examples and formulæ rather the method of abusing logic by means of subtleties than the method of rendering it a guide to truth.

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The Sophists hastened to profit by these lessons. They were essentially rhetoricians, who taught the art of speaking at time when all parties in Greece were ambitious of attaining this power. The Sophists made use of the art of reasoning, or rather of disputation; but they rendered it subordinate to their captious rhetoric, and only used it as a fit instrument to second their views and interests. Zeno armed reason against the senses; Gorgias armed it against itself. He found plausible reasons to prove, 1st, that nothing real exists; 2d, that, if any thing real did exist, we could not know it; 3rd, that, if we had any such knowledge, we could not transmit it to others on account of the uncertainty attached to language. These three maxims served for the three divisions of the book he wrote on Nature. He established these axioms on the strength of the argument drawn from the mobility of all things, and certain subtleties which he presses into his service.

Protagoras asserts that the understanding, the whole soul, consists in the faculty of sensation. Applying to this hypothesis all that had been said by the Eleatics on the mobility of sensible objects and the relative character of sensation, he is led to results which, though they differ in expression, do not in character, from those of Gorgias.