Imágenes de páginas
PDF
EPUB
[ocr errors]

5. Aristoteles Thiergeschichte, in zehn Büchern; Uebersetst und

crläubert, von Dr. Ph. H. Külb. Stuttgart, 1856. 6. Aristotle's History of Animals, in Ten Books. Translated by

Richard Cresswell, M. A., St. John's College, Oxford.

London : Henry G. Bohn, 1862. 7. Aristotle ; a Chapter from the History of Science, including

analyses of Aristotle's Scientific Writings. London, 1864. OOLOGY, like every other branch of physical science,

is in its nature essentially progressive. First the blade, then the ear, after that the full corn in the ear,' is a law no less in philosophy than in nature. Ever since the Creation the intellectual mind of man has been acquiring fresh stores of knowledge, generally, indeed, by slow and laborious steps, sometimes by rapid strides, as here and there some master mind has succeeded in moulding into some well-defined form the results of previous discoveries. Each succeeding generation inherits some valuable patrimony bequeathed to it by the speculations or discoveries of a former age, · For I doubt not thro' the ages one increasing purpose runs,

And the thoughts of men are widen'd with the process of the suns.' • The physical sciences are, commonly, not formed by one single act,' as Dr. Whewell has well said, they are not completed by the discovery of one great principle; on the contrary, they consist in a long continued advance, a series of changes, a repeated progress from one principle to another, different and often apparently contradictory.'** The torch of science, that burns in these days with a full and clear but continually increasing light, emitted for ages an unsteady flickering glare; at certain epochs it was fanned by the breath of some pre-eminently endowed inind--aliquo afflatu divino-into a clearer but still a transient flame, again perhaps for centuries to smoulder with an all but extinguished fire; yet he who now from the lofty pinnacle of the temple of science surveys with just pride the vast field, rich in promises for the future, which opens to his view, and fails to bear in mind the labours of those who, in ages past, have helped to rear the scaffolding or to build the fabric, commits a grave inistake indeed. The final form of each science'—we quote again the words of Dr. Whewell— contains the substance of each of its preceding modifications; and all that was at any antecedent period discovered and established ministers to the ultimate development of its proper branch of knowledge.'t

These remarks apply, it is true, more particularly, though not

* History of the Inductive Sciences,' i. p. 9.

† Ibid., p. 10.

exclusively, exclusively, to what we understand by positive science ; that is to say, to that method of inductive reasoning, by which from our knowledge of one or more particular facts we infer the general law of any phenomenon ; but at the same time we ought also to take into account the various speculations that have emanated from disciples of the metaphysical schools of ancient Greece, which, though doubtless generally barren in results, have still contributed something to the general fund. It is very curious to note how the physical theories of the ancients occasionally coincide with the discoveries of modern science, and who can say that their 'guesses at truth'- for they were generally nothing more- - have not had some real though unrecognised influence in directing the minds of future generations to the investigation of those laws which they have successfully determined. All those who have any conviction in the steady development of humanity,' a thoughtful writer has admirably remarked, “and believe in a direct filiation of ideas, will at once admit that the curious but erroneous speculations of the Greeks were necessary to the production of modern science.'* It would be easy to adduce instances in which the ancient philosophers, by some fortuitous speculation, appear to have anticipated modern discovery; their theories, however, for the most part, rested on no foundation ; they were simply guesses, their authors were quite unable to prove their truth. Democritus, it is said, maintained that the milky-way was only a cluster of stars. He was quite right, but he could not know the fact. The telescope of Galileo revealed it. The atomism of the philosopher of Abdera is identical with the Monadologie of Leibnitz, and although unquestionably distinct from the true atomic theory of Dalton and the moderns—the former being the affirmation of indefinite combinations, the latter the law of definite proportions'-it may perhaps be considered to contain its germ. † The principle of the astronomic system of Copernicus was foreshadowed by Philolaus and other disciples of the school of Pythagoras, for they considered the sun to be fixed, and attributed a motion to the earth.

All natural science, and indeed science of every kind, is to be referred,' as the learned German historian of Botany † has remarked, to the mingling together of two distinct sources, the observation of facts, and speculation upon the facts observed,' or to use the language of Whewell,Ş we may say that to the formation of science two things are requisite-facts and ideas; observation of things without, and an inward effort of thought, or in other words sense and reason. Neither of these elements, by itself, can constitute substantial general knowledge. The impressions of sense, unconnected by some rational and speculative principle, can only end in a practical acquaintance with individual objects; the operations of the rational faculties, on the other hand, if allowed to go on without a constant reference to external things, can lead only to empty abstraction and barren ingenuity. Real speculative knowledge demands the combination of the two ingredients-right reason, and facts to reason upon.

* * Biographical History of Philosophy,' by G. H. Lewes, i. p. 12. † Ibid., p. 153. Ernst H. F. Meyer, Geschichte der Botanik,' i. p. 3. § ‘History of the Inductive Sciences,' i. pp. 6, 7.

other

5

In the early ages of the world we may say without hesitation that there was no science in the true sense of the term. Knowledge for the simple sake of knowledge had no existence. Of speculative philosophy there is scarcely a trace to be found before the time of Thales, who may fairly be looked upon as the father of Greek speculation. It was the Greeks, moreover, who first developed this habit of mind; they first separated the speculative from the practical tendencies of mankind. Amongst the Shemitic nations barely a vestige of the scientific spirit is to be seen before the middle ages when the Arabs began to cultivate it, but it was not indigenous to the Oriental mind. Arabian science was essentially Greek, and borrowed from Aristotle and others of the metaphysical school of Greece.

The striking generalization of a modern philosopher, which has received the sanction of writers so eminent as Grote, Mill, and Lewes, is certainly very applicable to the development of the mind of the ancient Greek philosopher

. According to these authors there are three distinct and characteristic stages which history reveals to us in man's attempts to explain natural phenomena ; these stages have been named the supernatural, the metaphysical, and the positive. In the supernatural stage, to borrow the words of Mr. G. H. Lewes, man explains phenomena by some fanciful conception suggested by the analogies of his own consciousness. Nature is regarded as the theatre whereon the arbitrary wills and momentary caprices of superior powers play their varying and variable parts. Men are startled at unusual occurrences, and explain them by fanciful conceptions. A solar eclipse is understood, and unerringly predicted to a moment by positive science; but in the supernatural epoch it was believed that some dragon had swallowed the sun!' In the metaphysical stage man “explains phenomena by some à priori conception of inherent or superadded entities, suggested by the constancy observable in phenomena, which constantly leaves him to suspect that they are not produced by any intervention on the part of an external being, but are owing to the nature of the things themselves. Here the notion of capricious divinities is replaced by that of abstract entities, whose modes of action are, however, invariable, and in this recognition of invariableness lies the germ of science.' In this epoch Nature has a 'horror of a vacuum'; organised beings have 'a vital principle,' and matter has a vis inertiæ. In the third stage, man explains phenomena by adhering solely to these constancies of succession and coexistence ascertained inductively, and recognised as the law of Nature.'... In this positive stage "the invariableness of phenomena under similar conditions is recognised as the sum total of human investigation; beyond the laws which regulate phenomena it is idle to penetrate.' Grecian philosophy, as we have already stated, belonged to the metaphysical stage; to the stage of positive science neither Aristotle, nor Plato, nor any ancient philosopher ever arrived; but the progress from one to another of these stages has been gradual. The step from the supernatural stage to the metaphysical was one in the right direction, though it was not made without much opposition; that from the metaphysical to the positive we are accustomed correctly, we think, to date from Francis Bacon, the father of inductive science.

selves.'

!

Natural science, therefore, in the supernatural stage of the Greek mind had no existence whatever. The natural productions of the earth, whether river, sea, or mountain were identified with heroes, nymphs, and genii. The sun and moon were veritable personages, Helios and Selene, that drove their chariots—the horses of which lived on herbs that grew in the islands of the blessed. They possessed flocks and herds, and were endowed with other attributes of humanity. To the mind of the early Greek there was nothing absurd in such notions, they seemed perfectly natural and plausible. "Mythology is poetry to us; to the ancients it was religion and science. The animals that figured in the zoology of the early Greek were hydræ with nine heads, one of which was immortal; stags with golden antlers and brazen feet, birds that used their feathers as arrows, and fed on human flesh; and centaurs half men and half horses, with talking doves, Gorgons, harpies, and chimæras dire.' In the supernatural stage of the Hellenic mind these and many other fabulous monsters were doubtless regarded as veritable living forms. Again, the belief in gods and heroes naturally led the early Greek worshipper to suppose that these quasi-human personages had their favourite animals and plants; hence, it may readily be imagined, arose various popular superstitions with regard to them. That the progress from the mythopæic or supernatural, age to

the

the metaphysical one was effected only very gradually and in spite of much opposition will be apparent from the fact that even in the times of Socrates and Plato, at the very zenith, that is, of the development of the Grecian intellect, these great thinkers asserted their belief in the divinity of Helios and Selenc. How far this belief was spontaneous, or how far it was exacted by the intolerant religious spirit of the age, we will not presume to say ; at any rate, it contrasts strongly with the teaching of the first disciples of physical philosophy, Thales, Xenophanes, and Pythagoras, who a hundred years before had opposed the current theology, “recognising determinate properties, invariable sequences, and objective truth in nature, either dependent on willing or designing agents, or serving to these latter at once as an indispensable subject matter and as a limiting condition.' That Socrates professed to believe in the divinity of the sun and the moon is evident from the following conversation between him and Meletus:

Meletus.—This I say, that you entirely disbelieve in the gods. • Socrates.-0 wonderful Meletus, why do you say such things? Do not I consider the sun and moon to be gods, just like other men ?

Mel.-No; by Jupiter, O judges ! since he asserts that the sun is a stone and the moon earth.

Soc.--You are imagining you are accusing Anaxagoras, my dear Meletus ; thus you have a poor opinion of these your judges here, and suppose that they are so ignorant as not to know that the books of Anaxagoras of Clazomene teem with such remarks. And, in truth, the young men learn these things from me which they can buy for about a drachma in the orchestra, and thus laugh at Socrates, if he pretended he was the author of them, especially since they are so absurd.' †

No doubt the views of Socrates and Plato with regard to the divinity of the sun and moon were far in advance of many of their predecessors, though they showed also a retrograde step when compared with the philosophy of Anaxagoras. Subjects, moreover, which related to the laws of the physical world were not suitable topics for discussion in the mind of the pious Socrates; and when we bear in mind how jealously such speculations were looked upon by the illiterate and superstitious public, and how frequently and virulently they were made the butts for the scorn of the intolerant Aristophanes, we shall be in no degree surprised to find how slowly any advance in the knowledge of natural phenomena was made; how, too, in the writings of men inost distinguished for subtle intellect and patient research, the

* Grote, i. p. 496.
† Plato, ' Apol. Socr.' xiv. D. E. Ed. Stallbaum, Lips., 1850.

most

« AnteriorContinuar »