I cannot dismiss the system of the Apollonian without setting in contrast with it the discoveries of modern science respecting the relations of the air. Toward the world of life it stands in a position of wonderful interest. Decomposed into its constituents by the skill of chemistry, it is no longer looked upon as a homogeneous body; its ingredients have not only been separated, but the functions they discharge have been ascertained. From one of these, carbonic acid, all the various forms of plants arise; that substance being decomposed by the rays of the sun, and furnishing to vegetables carbon, their chief solid ingredient. All those beautifully diversified organic productions, from the mosses of the icy regions to the palms characteristic of the landscapes of the tropics—all those we cast away as worthless weeds, and those for the obtaining of which we Inter-dependence of animals and plants. expend the sweat of our brow—all, without any exception, are obtained from the atmosphere by the influence of the sun. And since without plants the life of animals could not be maintained, they constitute the means by which the aërial material, vivified, as it may be said, by the rays of the sun, is conveyed even into the composition of man himself. As food, they serve to repair the waste of the body necessarily occasioned in the acts of moving and thinking. For a time, therefore, these ingredients, once a part of the structure of plants, enter as essential constituents in the structure of animals. Yet it is only in a momentary way, for the essential condition of animal activity is that there shall be unceasing interstitial death; not a finger can be lifted without the waste of muscular material; not a thought arise without the destruction of cerebral substance. From the animal system the products of decay are forthwith removed, often by mechanisms of the most exquisite construction; but their uses are not ended, for sooner or later they find their way back again into the air, and again serve for the origination of plants. It is needless to trace these changes in all their details; the same order or cycle of progress holds good for the water, the ammonia; they pass from the inorganic to the living state, and back to the inorganic again; now the same particle is found in the air next aiding in the composition of a plant, then in the body of an animal, and back in the air once more. In this perpetual Agency of the sun. revolution material particles run, the dominating influence determining and controlling their movement being in that great centre of our system, the sun. From him, in the summer days, plants receive, and, as it were, store up that warmth which, at a subsequent time, is to reappear in the glow of health of man, or to be rekindled in the blush of shame, or to consume in the burning fever. Nor is there any limit of time. The heat we derive from the combustion of stubble came from the sun as it were only yesterday; but that with which we moderate the rigour of winter when we burn anthracite or bituminous coal was also derived from the same source in the ultra-tropical climate of the secondary times, perhaps a thousand centuries ago.

In such perpetually recurring cycles are the movements of material things accomplished, and all takes place under the dominion of invariable law. The air is the source whence all organisms have come; it is the receptacle to which they all return. Its parts are awakened into life, not by the influence of any terrestrial agency or principle concealed in itself, as Diogenes supposed, but by a star which is ninety millions of miles distant, the source, direct or indirect, of every terrestrial movement, and the dispenser of light and life.

Heraclitus asserts that fire is the first principle.

To Thales and Diogenes, whose primordial elements were water and air respectively, we must add Heraclitus of Ephesus, who maintained that the first principle is fire. He illustrated the tendency which Greek philosophy had already assumed of opposition to Polytheism and the idolatrous practices of the age. It is said that in his work, ethical, political, physical, and theological subjects were so confused, and so great was the difficulty of understanding his meaning, that he obtained the surname of "the Obscure." In this respect he has had among modern metaphysicians many successors. He founds his system, however, upon the simple axiom that "all is convertible into fire, and fire into all." Perhaps by the term fire he understood what is at present meant by heat, for he expressly says that The fictitious permanence of successive forms. he does not mean flame, but something merely dry and warm. He considered that this principle is in a state of perpetual activity, forming and absorbing every individual thing. He says, "All is, and is not; for though it does in truth come into being, yet it forthwith ceases to be." "No one has ever been twice on the same stream, for different waters are constantly flowing down. It dissipates its waters and gathers them again; it approaches and recedes, overflows and fails." And to teach us that we ourselves are changing and have changed, he says, "On the same stream we embark and embark not, we are and we are not." By such illustrations he implies that life is only an unceasing motion, and we cannot fail to remark that the Greek turn of thought is fast following that of the Hindu.

But Heraclitus totally fails to free himself from local conceptions. He speaks of the motion of the primordial principle in the upward and downward directions, in the higher and lower regions. He says that the chief accumulation thereof is above, and the chief deficiency below: and hence he regards the soul of a man as a portion of fire migrated from heaven. He carries his ideas of the transitory nature of all phenomena to their last consequences, and illustrates the noble doctrine that all which appears to us to be permanent is only a regulated and self-renewing concurrence of similar and opposite motions by such extravagances as that the sun is daily destroyed and renewed.

Physical and physiological doctrines of Heraclitus.

In the midst of many wild physical statements many true axioms are delivered. "All is ordered by reason and intelligence, though all is subject to Fate." Already he perceived what the metaphysicians of our own times are illustrating, that "man's mind can produce no certain knowledge from its own interior resources alone." He regarded the organs of sense as being the channels through which the outer life of the world, and therewith truth, enters into the mind, and that in sleep, when the organs of sense are closed, we are shut out from all communion with the surrounding universal spirit. In his view every thing is animated and insouled, but to different degrees, organic objects being most completely or perfectly so. His astronomy may be anticipated from what has been said respecting the sun, which he moreover regarded as being scarcely more than a foot in diameter, and, like all other celestial objects, a mere meteor. His moral system was altogether based upon the physical, the fundamental dogma being the excellence of fire. Thus he accounted for the imbecility of the drunkard by his having a moist soul, and drew the inference that a warm or dry soul is the wisest and best; with justifiable patriotism asserting that the noblest souls must belong to a climate that is dry, intending thereby to indicate that Greece is man's fittest and truest country. There can be no doubt that in Heraclitus there is a strong tendency to the doctrine of a soul of the world. If the divinity is undistinguishable from heat, whither can we go to escape its influences? And in the restless activity and incessant changes it produces in every thing within our reach, do we not recognize the tokens of the illimitable and unshackled?

The puerility of Ionian philosophy.

I have lingered on the chief features of the early Greek philosophy as exhibited in the physical school of Ionia. They serve to impress upon us its intrinsic imperfection. It is a mixture of the physical, metaphysical, and mystical which, upon the whole, has no other value than this, that it shows how feeble were the beginnings of our knowledge—that we commenced with the importation of a few vulgar errors from Egypt. In presence of the utilitarian philosophy of that country and the theology of India, how vain and even childish are these germs of science in Greece! Yet this very imperfection is not without its use, since it warns us of the inferior position in which we stand as respects the time of our civilization when compared with those ancient states, and teaches us to reject the assertion which so many European scholars have wearied themselves in establishing, that Greece led the way to all human knowledge of any value. Above all, it impresses upon us more appropriate, because more humble views of our present attainments and position, and gives us to understand that other races of men not only preceded us in intellectual culture, but have equalled, and perhaps surpassed every thing that we have yet done in mental philosophy.

Anaximander's doctrine of the Infinite.