date so that space would no longer appear independent of the deity; likewise, following Hobbes, they made a more fundamental distinction between space and matter. It took somewhat longer, however, for a philosophy of time to develop. Descartes had been unable to do it, partly because time was obviously a mode of thinking substance as well as of res extensa, but more because he considered motion as a mathematical conception in general and had failed to appreciate Galileo's ideal of its detailed quantitative formulation. When men gradually attempted, however, to make more precise the notions and interrelations of force, acceleration, momentum, velocity, etc., it was natural that they found themselves compelled to an exact statement of what they meant by time. As they grew more confident on this point, time came gradually to seem as natural and self-justifying a continuum as space, quite as independent of human perception and knowledge, and to be metaphysically disposed of on the same principles. This stage in the development of a philosophy of time we reach first distinctly in Barrow. Just as space had ceased to appear accidental to objects and relative to magnitudes, and became a vast, infinite substance existing in its own right (except for its relation to God) so time. ceased to be regarded merely as the measure of motion, and became a mysterious something ultimately of religious significance, but quite independent of motion, in fact measured now by it, flowing on from everlasting to everlasting in its even mathematical course. From being a realm of substances in qualitative and teleological relations the world of nature had definitely become a realm of bodies moving mechanically in space and time. CHAPTER VI GILBERT AND BOYLE HOBBES' classic works had appeared in the forties and fifties of the seventeenth century; Newton's Principia was finished in 1687. During the intervening generation English thought was affected to a considerable extent by the writings of men like More, Cudworth, and Barrow, but more powerfully moved by the discoveries and publications of the great physicist and chemist Robert Boyle. Newton's thinking on ultimate problems bears as obvious marks of his lucid and many-sided mind as it does of the religious metaphysic of the Cambridge leader. For Boyle, although not commonly recognized as such, was a thinker of genuine philosophical calibre. But before we attempt a presentation of the fundamentals of Boyle's philosophy, it will be helpful to bring together a few threads which should now be united in our minds as we pass on to Newton via the metaphysics of the father of modern atomic chemistry. More's conception of a 'spirit of nature,' an active, nourishing, generating, directing agent, through whom the will of God becomes expressed in the world of matter, is apt to be somewhat puzzling to modern students, though in essence the notion is simple and it came to play a quite understandable part in the newlyevolving philosophy of science. Its connexions with the ancient idea of the soul of the world' and its similarity of function in the world at large to the animal spirits' within the nervous and circulatory system of an individual have been already remarked upon. More, it will be remembered, had insisted that this spirit of nature is an incorporeal, spiritual being, though without conscious intelligence or purpose, and had pounced upon it to explain such phenomena as gravity and magnetism, which seemed to him obvious evidence of non-mechanical forces in nature. Boyle, too, is convinced that clear thinking must admit something of the sort, and it is of central importance in Newton. We need a somewhat larger background for this conception. (A) The Non-Mathematical Scientific Current Back in the days of Kepler and Galileo, besides the exact mathematical movement in science, so powerfully advanced by their achievements and bringing in its train the remarkable metaphysical revolution which it seemed to imply, there was another scientific current under way, flowing by slower and more tentative steps, but none the less scientific in interest and fruitfulness. Its method was wholly empirical and experimental rather than mathematical, and it was primarily in connexion with this other current that attempts to give science a correct metaphysical groundwork made a quite positive and definite appeal to this spirit of nature,' or, as it was more commonly called, ethereal spirit.' William Gilbert, the father of scientific magnetism, whose classic work On the Loadstone and Magnetic Bodies appeared in the year 1600, was one of the luminaries of this non-mathematical scientific current. We shall not pause for a study of the details of his work, but the conviction into which he was led by the phenomena of magnetism, that the earth is fundamentally a huge magnet1, is of interest and importance. Gilbert conceives the interior of the earth as composed of a homogeneous magnetic substance; the earth's 'William Gilbert of Colchester, On the Loadstone and Magnetic Bodies, Mottelay translation New York, 1893, p. 64, ff. Gilbert,p. 313, ff, cohesion and likewise its diurnal revolution about its ; poles being thus accounted for, since a spherical loadstone, floated in water, moves circularly on its centre to become conformed to the earth on the plane of the equator." Moreover, as all but the very surface of the earth is of a homogeneous structure, the geometrical centre of the earth is also the centre of its magnetic movements1. Gilbert was one of the earliest champions in England of the Copernican theory as regards the diurnal revolution of the earth he did not accept the more radical position that the earth also revolves around the sun, though holding that the latter is the first mover and inciter of the planetary motions. Further, it is to Gilbert's experiments on magnetism that we owe the first beginnings of the use and conception of the word 'mass as we find it later matured in Newton. According to Gilbert, the strength and reach of a loadstone's magnetism varies according to its quantity or mass", that is, if it be of uniform purity and from a specified mine. Galileo and Kepler borrowed the notion of mass from Gilbert in this sense and connexion. Now Gilbert, like the other fathers of modern science, was not content simply to note and formulate the results of his experiments; he sought ultimate explanations of the phenomena. How can a loadstone attract a piece of iron that is separated from it in space ? His answer in essence was one which had been current in ancient times; magnetism is interpreted animistically. Magnetic force is something' animate, it "imitates a soul," nay, it " surpasses the human soul while united to an organic body," because though the latter uses reason, sees many things, investigates many more; but however well equipped, it gets light and the beginnings of knowledge from the outer senses, as from beyond a barrier-hence the very many igno Gilbert, p. 331. Gilbert, p. 150. Gilbert, p. 344. rances and foolishnesses whereby our judgments and our life-actions are confused, so that few or none do rightly and duly order their acts."s But the magnet sends forth its energy "without error... quick, definite, constant, directive, motive, imperant, harmonious." Thus the earth, since it is itself a great magnet, has a soul, which is none other than its magnetic force. "As for us, we deem the whole world animate, and all globes, all stars, and this glorious earth, too, we hold to be from the beginning by their own destinate souls governed and from them also to have the impulse of self-preservation. Nor are the organs required for organic action lacking, whether implanted in the homogenic nature or scattered through the homogenic body, albeit these organs are not made up of viscera as animal organs are, nor consist of definite members."10 The power of this magnetic soul to act at a distance, which especially interested Gilbert, he explained by the conception of a magnetic effluvium emitted by the loadstone. This effluvium he supposes to reach out around the attracted body as a clasping arm and draw it to itself; yet it is nothing corporeal at all; it "must needs be light and spiritual so as to enter the iron"; it is a breath or vapour which awakens within the attracted body a responding vapour. It is thus apparent that although Gilbert calls this magnetic effluvium incorporeal and spiritual, he does not mean that it is unextended or absolutely non-material in the Cartesian sense, but only that it is extremely thin like a rare atmosphere12. It is unlike matter in being penetrable and a motive power. The earth and every other astronomical body send out these magnetic effluvia to certain spatial limits, and the surrounding incorporeal ether thus composed shares the diurnal rotation of the body13. Beyond this ethereal vapour there is void space, in which the suns and planets, Gilbert, p. 311. Gilbert, p. 349. 10 Glbert, p. 309. 11 Gilbert, p. 106, ff. 13 Gilbert, p. 326. |