« ПредишнаНапред »
What can a modern Englishman do but accept such of the facts as appear to him probable and coherent? That Aristotle was, in the language of our times, a gentleman of birth and fortune, who, simply from an ardent love of knowledge, devoted himself to philosophy; that, born at Stagira, a town of northern Greece, situated in what is now called the Gulf of Contezza, he migrated to Athens, the intellectual capital of Greece and of the world, where Plato was then teaching; that, after many years of laborious application, his reputation was such that it brought an invitation from Philip of Macedon to undertake the education of the young Alexander-are facts, we presume, that we may accept without distrust. There is one trait of character ascribed to Aristotle which we hope also we may believe in this great thinker, one of the most indefatigable and powerful of the class that has lived upon the earth, was a tender and warm-hearted man, capable of love and of ardent friendship.
"His health," says Mr Lewes in that general summary of personal details which make up for us the picture of a man, "was, like that of most ardent brain-workers, delicate. He was short and slender in person; he had small eyes and an affected lisp. Somewhat given to sarcasm in conversation, he made, of course, many enemies. On hearing that some one had vituperated him in his absence, he humorously said, 'If he pleases, he may beat me too-in my absence.' His heart was kind, as was manifest in certain acts, and is expressed in this saying, 'He who has many friends has no friends,' which profoundly touches the very core
One of the last and most conspicuous incidents of his life appears to corroborate this impression of his affectionate character. When, upon the death of Alexander, the Macedonian party in Athens lost their power, and Aristotle, who belonged to this party, was exposed to the malice of his enemies, the worst charge these could bring against him was, that he had paid. divine honours to his wife and to his friend. He had burned the one and raised a statue to the other in a too sacred manner, or too sacred locality-thus infringing on the rights and privileges of the gods. In liberal and enlightened Athens, if a man was to be destroyed, the surest way was to represent him as a profane person-a despiser of the gods; to accuse him, in fact, of irreligion, or heresy of some kind. An incautious or too ambitious testimony of affection was the impiety alleged against our philosopher. He retired, we are told, before the coming storm. Mindful of the death of Socrates, he refused to the Athenians a second opportunity of disgracing the republic.
Mr Lewes opens his criticism on the science of Aristotle with the following general account of his physics:—
"The physical writings of Aristotle still extant are the eight books of 'Physics,' the four books 'On the Heavens,' the two books on 'Generation and Corruption,' with the 'Meteorology' and the Mechanical Problems.' The contents of these works very slightly correspond with their titles, according to modern conceptions. The sciences which we class under the heads of Physics and Astronomy are in no sense represented in them. There is no attempt to sketch the laws of Statics, Dynamics, Optics, Acoustics, Thermotics, or Electricity. There is nothing beyond metaphysical disquisitions sug gested by certain physical phenomena; wearisome disputes about motion, space,
infinity, and the like; verbal distinctions, loose analogies, unhesitating assumptions, inexpressibly fatiguing and unfruitful. They have furnished matter for centuries of idle speculation, but few beams of steady light to aid the groping endeavours of science. We cannot say that in every point he is altogether wrong—on some points he was assuredly right; but these are few, isolated, without bearing on the rest of his speculations, and without influence on research. I shall therefore analyse these works much more rapidly and briefly than the works on Biology."
We are thus inducted into some of those earlier doctrines, or methods of thinking upon physical topics, which belong not exclusively, indeed, to Aristotle, but to the age in which he lived. We are taught the principle of Contraries, once a theme of learned disquisition throughout Europe
"There are," says Aristotle, "three principles: Matter, Form, and Privation. In every phenomenon we can distinguish the substance and its form; but as the form can be only one of two contraries, and as only one of these two can exist at each moment, we are forced to admit the existence of a third principle, Privation, to account for the contrary which is absent. Thus a man must be either a musician or a non-musician; he cannot be both at the same time: and that which prevents his being one of these is the privation of the form."
Then we have a definition of nature as the principle of Motion and Rest ;" and of Movements it is added, that "those are called natural which are self-moved." Further on we are told that there are two great classes of movements1. The natural; and, 2. The violent or unnatural. Fire ascends and a stone descends by natural movement. A stone may be made to ascend, but this is owing to violence. Some external motor causes it to ascend; by its natural movement the stone would never rise, but always fall. For a similar reason, fire may be made to descend; but, left to its natural movement, it will only ascend. We have in these few passages a fair specimen of that mode of thought, or false method, which
Aristotle and his contemporaries brought to the study of nature. Men of acute intellect, eager to give an explanation of all things, applied at once to the phenomena before them some abstraction or generalisation ready made in the language of daily use. They should have occupied themselves, we are apt to say, with the collection of facts; they should have formed generalisations from this careful observation of facts, and then proceeded to reason on these generalisations, verifying their inferences at each step by fresh appeals to observation and experiment. Such is the true method of science. But we perceive very clearly that the generalisations from which the man of science permits himself to reason deductively (because originally formed from careful induction) were not then in existence, and could not have been then in existence. Were these men to be silent? If it is said they should have occupied themselves with observation and experiment, the answer is at hand: No men ever did, or could, pursue to advantage a train of observation or experiment, unless under the guidance of some hypothesis or conjecture. There is some guess of their own they seek to establish, or guess of others they seek to overthrow. Conjecture and experiment must at all times proceed together. These early sages were to blame, not so much for what they did, as what they left undone. They conjectured much and experimented little but it was something to conjecture; the rest of the world neither observed nor conjectured.
The false method of the Greek philosopher did not consist in any theoretical neglect of observation. He knew the value of a fact as well as his modern successor; but he lived at a time when those generalisations formed by careful observation had not yet been made. He himself might be helping to make them, but as yet they were not. What could he do but avail himself of such ideas or generalisations as an
uncritical experience had produced, and which, perhaps, were incorporated into the very language of daily use? Gravity, or the attraction of matter to matter, is a generalisation of modern science; it is formed from induction or observation, and we permit ourselves, therefore, to reason on it with confidence. It enters into our explanation of this or that still perplexing phenomenon. The principle of contraries was the result of no careful induction; it was snatched up in haste. Heat drives out cold, and cold heat. Was there not a principle here of universal application? So amongst motions of inanimate bodies were not some natural, just as certain motions in our own organism are felt to be natural? It was a rude analogy—an unauthorised generalisation.
The difference between the false method and the true is the inevitable result of position in the course of time, or process of development. The modern man of science reasons from generalisations which are the results of a hitherto universal experience; but, waiting the formation of these, the earlier sage reasoned on something which was the result of a scanty experience or a fanciful analogy. He had nothing better to
What, let us ask ourselves, is the kind of observation on which science is founded, or with which science commences? It is not the mere use of our senses, or the mere perception of objects. Nor do we call by the name of Science that practical knowledge of the qualities of things so essential to life, as that fire burns, or food nourishes. Such knowledge as the senses directly give us lies, we need not say, at the basis of all science, but is not science itself. There are two kinds of observation on which science depends: 1st, When we detect similarities between things or events which at first sight appeared widely different, and thus establish an essential identity where only diversity had presented itself; and, 2d, When, amongst the
series of events perpetually occurring around us, we select those which are unalterably united in never-failing sequence, or relation of cause and effect, and classify them apart from those whose connection is not invariable. And now let us ask, what motive or passion it is that prompts to observation of this subtle kind? It is not our daily wants or appetites. These may greedily seize upon knowledge of a scientific kind, which they can make subservient to them; they do not originally lead to it. Science originates in that noble curiosity with which men, or at least some men, are endowed-the desire to understand all, to see all as with the eye of intellect; to harmonise what seems confused; to represent to themselves the whole in its completeness. And now one question more, Would you check this curiosity till all legitimate appliances were ready for its gratification; would you prevent it from asking questions and giving answers till it had been strictly demonstrated what kind of questions were to be asked, and how precisely the answer was to be obtained? Manifestly such restrictions, instead of leading to a more rapid progress in knowledge, would have rendered all effort and all development impossible; they would have killed at once the noble curiosity we are speaking of. Honour to those who, stimulated by this generous passion, persisted energetically to think, in the full confidence that finally the human intellect would triumph over all difficulties.
Proceeding in our analysis, we come upon a curious notion relative to motion in a vacuum :—
"Aristotle argues that in vacuo motion is impossible. In a void there can be no difference of place; and motion implies difference of place. He then adds, that projectiles continue moving after the original motor ceases to be in contact with them, either, as some say, by reaction, or by the motion of the
adds, no one can say why, in vacuo, a body once set in motion should ever stop; since why rather here than there? Con
sequently, it must rather remain in necessary rest, or, if in motion, in endless motion, unless some stronger interferes.' Aristotle lived before the airpump had enabled us to produce a vacuum, and, speculating only on motion through the air, he found in the pulses of the air itself a cause for continuous motion. The mode of reasoning was natural enough. There is much of this kind of ingenious error in the physics of Aristotle. But if we do not blame, neither can we be called upon to admire.
Aristotle missed our modern doctrine of inertia, or rather our doctrine that every change demands a cause (according to which a moving body would move on for ever if nothing intervened to arrest or retard its motion), but he is credited with having ascertained several of our scientific laws of motion.
"The principle of vertical velocities' was certainly known to him. This has been denied; but Galileo himself says that he found it in Aristotle, and doubtless alludes to the following passage:The same force will raise a greater weight in proportion as the force is applied at a longer distance from the fulcrum, because it then describes a larger circle; and a weight which is farthest removed from the centre, is made to move through the greatest space.'
"He also gained a glimpse of the parallelogram of forces. Poselger thinks his statement of it superior in elegance and precision to that given by Kant. Yet, in spite of this, I must still think that Aristotle only gained a glimpse of the law, as he did of the principle of ' vertical velocities,' since he failed to see its far-reaching importance, and made little or no use of it."
It illustrates the difficulty that attends upon forming an accurate estimate of the science of Aristotle, that this very explanation he gives of the power of the lever has been differently interpreted by his commentators. Some have understood that when he accounts for the greater force of a weight at the long arm of the lever by the circumstance that it describes a larger circle, he was alluding to the " marvellous properties of the circle," of
which he elsewhere discourses in a mysterious manner. Mr Lewes, it will be seen, adheres to the more generous interpretation, and understands Aristotle to mean what a modern lecturer would mean; in describing a larger circle, the weight or force would be acting a longer time.
To abridge Mr Lewes's analysis is no part of our task. Neither could it be abridged with any propriety. The reader who is interested at all in the subject will never find it too long. But we shall continue to select a few specimens from it, both to illustrate the Aristotelian mode of thinking, and also to test some of the startling eulogies which even such men as Cuvier and St Hilaire have bestowed upon the mighty Stagirite."
The work on Meteorology has been lately translated into French by M. Barthélemy St Hilaire, who appears to be very encomiastic in his annotations. Mr Lewes, while admitting that all has been done that could be expected of an observer who had no thermometer, no barometer, no hygrometer, no anemometer, no instrument of any kind whatever, will not admit that observations made under these disadvantages have much scientific value. "The work shows," he says, what could and what could not be effected by observation, unassisted by instruments. Aristotle, equally with moderns, makes heat the chief agent in meteorologic changes. But this is general, qualitative knowledge, and science demands quantitative knowledge." As our classification of the sciences had not yet been formed, it will not be supposed that Aristotle's work exactly corresponds with what we should understand by a treatise on meteorology. It embraces what we should call a heterogeneous variety of topics. The four elements are discussed-fire, air, water, earth
of which all mundane bodies are composed. To these are added a fifth element, an ether, which fills supra
mundane space, of which little, it seems, is said, except that it is endowed with circular movement. Explanations are given of shooting stars, comets, and the Milky Way, the formation of rivers, the saltness of the sea, clouds, fogs, dew, the winds, and other phenomena which we more distinctly recognise as meteorological. It is worth noticing, that although Democritus had already asserted of the Milky Way that it was a cluster of stars, Aristotle prefers to regard it as an exhalation from the earth suspended in the air. We moderns, judging from our own position, are disposed, in a case like this, to give the palm of superior sagacity to Democritus. But, in fact, they were both mere guesses. The telescope has revealed to us that Democritus made the happier conjecture; but in the position which the two men occupied, one guess was as meritorious as the other.
"On these multifarious topics," Mr Lewes remarks, "his theories, as may be imagined, are mostly wide of the mark, but they often display remarkable sagacity, and bear the stamp of an earnest investigating mind. The large accumulation of facts is very noticeable; but rather, I think, on account of the attitude of mind which impelled him to make such an accumulation, and to insist with so much emphasis on the value of facts, than, as M. Barthélemy St Hilaire would have us believe, because the facts themselves display any noticeable sagacity. M. St Hilaire is at great pains, in his commentary, to point out every occasion on which his hero is correct, or approaches correctness in facts; but a little reflection reveals that in the majority of such cases the facts are such as lie open to universal observation, implying no merit, therefore, in the observer, while in no case have they quantitive precision. It is for its method rather than its results that this treatise is remarkable."
We pass on to the Anatomy and Physiology of the ancient sage. Here it will be new to many an English reader to learn that some eminent Frenchmen have discovered in Aristotle a quite surprising accuracy, and even a marvellous
anticipation of modern science. For ourselves, we have been accustomed to regard such encomiums as a harmless display of eloquence, and perhaps of vanity-nothing better, nothing worse. The man of science loves occasionally to add to his own proper honours the graceful plume of scholarship. With a cheap magnanimity he exalts the dead. He varies his lecture, or enlivens his page, with a burst of classical enthusiasm. It rings hollow to our ear-fictitious or pedantic-but it is harmless enough. No men of science now dream of reviving the authority of Aristotle; that is, of taking any of their facts out of his pages, or any one of their opinions. Nevertheless, by those who, like the author before us, are bent on framing an accurate estimate of what a great man of past times really accomplished, such exaggerations cannot be contemplated with perfect indifference. Lewes undertakes the rather ungracious task of reducing this applause to its due proportions.
"The eulogies," he observes, "lavished on Aristotle as a biologist, even by men whose own special knowledge might have made them the severest critics, remind us rather of the tone adopted in the middle ages than of the more circumspect and critical language of our own age. In Aristotle,' says Cuvier, ‘everything amazes, everything is prodigious, everything is colossal. He lived but sixty-two years, and he was able to make thousands of observations of extreme delicacy, the accuracy of which the most rigorous criticism has never been able to impeach.' This rhetorical exaggeration is painfully insincere; no one better than Cuvier could have known the worthlessness of Aristotle's observations on all points which were not open to the common eye; but that servility, too common amongst Frenchmen, which makes them eager to do homage to every established reputation, made Cuvier forget his own knowledge, and bow his head before the blinding splendour of a great renown.
"Little less rhetorical is De Blainville, who, though notorious for his love of contradiction, dared not whisper a word against 'le grand Stagirite.' is the natural sciences,' he says, ' which