1. Extract from Dr. Whewell. A short treatise on Sophistical Proofs winds up the series of Aristotle’s works on logic. Then follow his voluminous writings on physics. In these we have no direct interest. To show, however, how the logical ideas of Aristotle affected his views in this department, we shall take the liberty of extracting a passage from Dr. Whewell’s History of the Inductive Sciences, vol. i. sec. 2; “The Aristotelian Physical Philosophy.”
2. The books on physical facts. “The principal treatises of Aristotle are, the eight books of Physical Lectures, the four books Of the Heavens, the two books Of Production and Destruction, for the book Of the World is now universally acknowledged to be spurious, and the Meteorologics, though full of physical explanations of natural phenomena, does not exhibit the doctrines and reasonings of the schools in so general a form; the same may be said of the Mechanical Problems. The treatises on the various subjects of natural history, On Animals, On the Parts of Animals, On Plants, On Physiognomies, On Colours, On Sounds, contain an extraordinary accumulation of facts, and manifest a wonderful power of systematising; but are not works which expound principles, and therefore do not require to be here considered.
3. The Physical Lectures. “The Physical Lectures are the works concerning which the well-known anecdote is related by Simplicius, a Greek commentator of the sixth century, as well as by Plutarch. It is said that Alexander the Great wrote to his former tutor to this effect: ‘You have not done well in publishing these Lectures, for how shall we, your pupils, excel other men if you make that public to all which we learned from you?’ To this Aristotle is said to have replied: ‘My Lectures are published and not published; they will be intelligible to those who heard them and to none beside.’ This may very easily be a story inscribed and circulated among those who found the works beyond their comprehension; and it cannot be denied that to make out the meaning and reasoning of every part would be a task very laborious and difficult, if not impossible. But we may follow the import of a large portion of the work with sufficient clearness to apprehend the character and principles of the reasoning; and this is what I shall endeavour to do.
4. His use of words. “The author’s introductory statement of his view of the nature of philosophy falls in very closely with what has been said, that he takes his facts and his generalisations as they are implied in the structure of language. ‘We must in all cases proceed,’ he says, ‘from what is known to what is unknown.’ This will not be denied; but we can hardly follow him in his inference. He adds, ‘We must proceed, therefore, from universal to particular. And something of this,’ he pursues, ‘may be seen in language; for names signify things in a general and indefinite manner, as circles, and by defining we unfold them into particulars.’ He illustrates this by saying, ‘thus children at first call all men father, and all women mother, but afterwards distinguish.’
5. “In accordance with this view he endeavours to settle several of the great questions concerning the universe, which had been started among subtle and speculative men, by unfolding the meaning of the words and phrases which are applied to the most general notions of things and relations. We have already noticed this method. A void. A few examples will illustrate it further. Whether there was or was not a void, or place without matter, had already been debated among rival sects of philosophers. The antagonist arguments were briefly these: there must be a void because a body cannot move into a space except it is empty, and therefore without a void there could be no motion; and, on the other hand, there is no void, for the intervals between bodies are filled with air, and air is something. These opinions had even been supported by reference to experiment. On the one hand, Anaxagoras and his school had shown, that air when confined resisted compression, by squeezing a blown bladder, and pressing down an inverted vessel in the water; on the other hand, it was alleged that a vessel full of fine ashes held as much water as if the ashes were not there, which could only be explained by supposing void spaces between the ashes. Aristotle decides that there is no void on such arguments as this:—In a void there could be no differences of up and down; How Aristotle proves that there is none. for as in nothing there are no differences, so there are none in a privation or negation; but a void is merely a privation or negation of matter; therefore, in a void, bodies could not move up and down, which it is in their nature to do. It is easily seen that such a mode of reasoning elevates the familiar forms of language, and the intellectual connections of terms to a supremacy over facts; making truth depend upon whether terms are or are not primitive, and whether we say that bodies fall naturally. In such a philosophy every new result of observation would be compelled to conform to the usual combinations of phrases as they had been associated by the modes of apprehension previously familiar.
6. Before and After. “It is not intended here to intimate that the common modes of apprehension, which are the basis of common language, are limited and casual. They imply, on the contrary, universal and necessary conditions of our perceptions and conceptions; thus all things are necessarily apprehended as existing in time and space, and as connected by relations of cause and effect; and, so far as the Aristotelian philosophy reasons from these assumptions, it has a real foundation, though even in this case the conclusions are often insecure. We have one example of this reasoning in the eighth book, where he says that there never was a time in which change and motion did not exist; ‘for if all things were at rest, the first motion must have been produced by some change in some of these things; that is, there must have been a change before the first change:’ and again, ‘How can before and after apply where time is not? or how can time be when motion is not?’ ‘If,’ he adds, ‘time is a mensuration of motion, and if time be eternal, motion must be eternal.’ But we have sometimes principles introduced of a more arbitrary character, and, besides the general relations of thought, the inventions of previous speculators are taken for granted; such, for instance, as the then commonly received opinions concerning the frame of the world. From the assertion that motion is eternal, proved in the manner just stated, Aristotle proceeds by a curious train of reasoning to identify this eternal motion with the diurnal motion of the heavens. ‘There must,’ he says, ‘be something which is the first moved;’ this follows from the relation of causes and effects. Again, ‘Motion must go on constantly, and therefore must be either continuous or successive. Now what is continuous is more properly said to take place constantly, than what is successive. Better and Worse. Also the continuous is better; but we always suppose that which is better to take place in nature, if it be possible.’ We see here the vague judgment of better and worse introduced, as that of natural and unnatural was before into physical reasonings.
7. Circularity of motion. “I proceed with Aristotle’s argument, ‘We have now, therefore, to show that there may be an infinite, single, continuous motion, and that this is circular.’ This is, in fact, proved, as may readily be conceived, from the consideration that a body may go on habitually revolving regularly in a circle. And thus we have a demonstration, on the principles of this philosophy, that there is and must be a first mover, revolving eternally with a uniform circular motion.
“Though this kind of philosophy may appear too trifling to deserve being dwelt upon, it is important for our purpose so far to exemplify it that we may afterwards advance, conscious that we have done it no injustice.
8. Elements of the universe. “I will now pass from the doctrines relating to the motions of the heavens to those which concern the material elements of the universe. And here it may be remarked, that the tendency (of which we are here tracing the development) to extract speculative opinions from the relations of words must be very natural to man; for the very widely-accepted doctrine of the four elements, which appears to be founded upon the opposition of the adjectives hot and cold, wet and dry, is much older than Aristotle, and was probably one of the earliest of philosophical dogmas. The great master of this philosophy, however, puts the opinion in a more systematic manner than his predecessors.
9. Contrarieties. “‘We seek,’ he says, ’the principles of sensible things, that is, of tangible bodies. We must take, therefore, not all the contrarieties of quality, but those only which have reference to the touch. Thus black and white, sweet and bitter, do not differ as tangible qualities, and therefore must be rejected from our consideration.
“‘Now the contrarieties of quality which refer to the touch are these, hot, cold; dry, wet; heavy, light; hard, soft; unctuous, meagre; rough, smooth; dense, rare.’ He then proceeds to reject all but the four first of these, for various reasons; heavy and light because they are not active and passive qualities; the others because they are combinations of the four first, which, therefore, he infers to be the four elementary qualities.
“‘Now in four things there are six combinations of two; but the combinations of two opposites, as hot and cold, must be rejected; we have, therefore, four elementary combinations which agree with the four apparently elementary bodies; air is hot, wet, (for steam is air,) water is cold and wet, and earth is cold and dry.’
10. Bacon infected by this nominalism. “It may be remarked that this disposition to assume that some common elementary quality must exist in the cases in which we habitually apply a common adjective, as it began before the reign of the Aristotelian philosophy, so also survived its influence. Not to mention other uses, it would be difficult to free Bacon’s Inquisitio in Naturam Calidi, ‘Examination of the Nature of Heat,’ from the charge of confounding together very different classes of phenomena under the cover of the word hot.
“The rectification of these opinions concerning the elementary composition of bodies belongs to an advanced period in the history of physical knowledge, even after the revival of its progress.
11. Absolute and relative levity. “The Aristotelian doctrines concerning motion are still founded upon the same mode of reasoning from adjectives; but in this case the result follows, not only from the opposition of the words, but also from the distinction of their being absolutely and relatively true. ‘Former writers,’ says Aristotle, ‘have considered heavy and light relatively only, taking cases where both things have weight, but one is lighter than the other; and they imagine that in this way they defined what was absolutely (ἁπλῶς) heavy and light.’ We now know that things which rise by their lightness do so only because they are pressed upwards by heavier surrounding bodies; and this assumption of absolute levity, which is evidently gratuitous, or rather merely nominal, entirely vitiated the whole of the succeeding reasoning. The inference was that fire must be absolutely light, since it tends to take its place above the three other elements; earth absolutely heavy, since it tends to take its place below fire, air, and water. The philosopher argued also with great acuteness that air, which tends to take its place below fire and above water, must do so by its nature, and not in virtue of any combination of heavy and light elements. For if air was composed of two parts, which give fire its levity, joined to other parts which produce gravity, we might assume a quantity of air so large that it should be lighter than a similar quantity of fire, having more of the light parts. It thus follows that each of the four elements tends to take its own place, fire being the highest, air the next, water the next, and earth the lowest. The whole of this train of errors arises from fallacies which have a verbal origin; from considering light as opposite to heavy, and from considering levity as a quality of a body, instead of as the effect of surrounding bodies.”