device, more than of the other; seeing that by adopting spiral lines (the supposition which comes nearest to the sense and the fact) the thing is accomplished, and those phenomena are saved. And (which is the chief point) these spirals are nothing else than defections from perfect circular motion, whereof the planets are impatient. For in proportion as substances degenerate in purity and freedom of development, so do their motions degenerate. Now it happens, that as in point of velocity the higher planets move faster, and the lower less fast; so also the higher planets make spirals more closely coincident and coming nearer to circles, the lower make spirals more disjoined and further apart. For continually as they descend they recede more and more both from that height of velocity and that perfection of circular motion, in regular order. Yet in this the planets agree (as being bodies that retain much of a common nature, though otherwise differing) that they have the same limits of deflexion. For neither does Saturn come back within the tropics, nor the moon go forth beyond the tropics (and yet with regard to the wandering of Venus there are certain traditions and observations not to be overlooked); but all the planets, whether the higher or lower, as soon as they reach the tropics, turn back and retrace their course, disliking the smaller spiral in which they would have to move if they approached nearer the poles; and shrinking froın that loss of motion, as from the destruction of their nature. For however in the starry heaven both the stars near the poles and the stars about the equinoctial maintain their ranks and stations, one being kept in order by another, with a perfect and equable constancy; yet the planets seem to be of such a mixed nature as not willingly to endure either a shorter circle or a larger. These views then concerning the celestial motions appear to me a little better than the carrying by force, the repugnance of motions, the different polarity of the zodiac, the inverted order of velocity, and the like; which have no manner of agreement with the nature of things, however they keep peace, such as it is, with the calculations. Neither were the better astronomers blind to these things; but being intent on their art, and foolishly attached to perfect circles, and catching at subtleties, and too servile to philosophy, they scorned to follow nature. But this imperious disposition of philosophers towards nature is worse even than the simplicity and credulity of the vulgar; if a man disdains a plain thing because it is plain. And yet a vast evil it is and of very wide extent, that the human wit, not being able to match nature, must needs put itself above nature. But now we must inquire whether that single and simple motion, in a circle and spiral, from east to west, on certain poles south and north, ends and terminates with the heaven, or extends likewise to things below. For it will not be open to us to invent here in the regions next us such things as they suppose in the heavens. If therefore in these regions also this motion be found, it will appear that in heaven likewise it is, under the conditions of a common or cosmical nature, such as we experience it. First then it is plain that it is not confined within the limits of heaven. But the demonstrations and evidences on this point I have fully treated in my "anticipation" concerning the ebb and flow of the sea; 1 to which men are therefore referred; and taking this for settled and concluded, I will proceed to the other motions of celestial bodies. These I have said are not cosmical, but mutual, or having relation one to another. There are four kinds of motions visible in heavenly bodies besides that which I have called cosmical, which is the diurnal motion by spirals within the tropics. For the stars either rise higher and again sink lower, so as to be further off and nearer the earth; or they turn and wind from side to side of the zodiac, running out more to the south or more to the north, and forming what they call dragons; or they vary in velocity and likewise in direction of motion (for I put these two together), proceeding sometimes quicker, sometimes slower, sometimes in progression, sometimes in regression, sometimes likewise stopping and remaining stationary; or they are attached and circumscribed at a greater or less distance from the sun. The causes and natures of these motions I will only give in general and by heads; for this the plan of my work here demands. But to pave and open the way for this, I must say without reserve what I think with regard to certain philosophical doctrines, as well as astronomical hypotheses, and likewise with regard to the observations of astronomers in various ages, upon which they build their art; all which appear to me full of error and confusion. There are some axioms then, or rather opinions, which being received by philosophers, transferred into astronomy, and unhappily believed, have corrupted the art. Of these my rejection and judgment will be simple: for I have no time to spend in confutations. The first is, that all things above the moon inclusive are incorruptible, and not subject to new generations or changes of any kind. Of this I have spoken elsewhere, as being a superstition and a vanity. But it is the fountain from which springs that vast evil, that upon every anomaly astronomers frame new and (as they think) corrected theories, and often apply to things that are as it were fortuitous causes eternal and invariable. The second is, that the heaven (as consisting of a fifth essence, and of no elementary substance) admits not of those turbulent actions of compression, relaxation, repulsion, submission, and the like, that seem to be produced by a certain hardness and softness of bodies, which are regarded as elementary qualities. But this assertion is an insolent and licentious repudiation of fact and sense. For wherever a natural body is placed, there also is resistance, and that in proportion to the body. And wherever there are natural bodies and local motion, there is either repulsion, or yielding, or division; for these things above mentioned, namely, compression, relaxation, repulsion, yielding, with many others, are universal passions of matter everywhere. And yet from this fountain has flowed that multiplication of circles complicated at pleasure, which they will nevertheless have to be so adapted to each other, and to move and turn with such smoothness and slipperiness one within the other, that there is no obstruction at all, no fluctuation; all which are plainly fanciful, and trample upon the nature of things. The third is, that all natural bodies have their own proper motions; and if any be found to have more than one, that all the rest come from elsewhere, and from some separate moving body. Than which nothing falser can be devised, seeing all bodies by the manifold consent of things are endued likewise with many motions, some ruling, some obeying, and some also lying dormant unless exerted; and proper motions of things there are none, except exact measures and modes of common motions. Hence again has come forth a separate primum mobile, and heavens above heavens, and a continuous chain of new structures, to meet the demands of such different motions. The fourth is, that all celestial motions are performed in perfect circles; a thing very cumbrous, which has produced for us those prodigies of eccentrics and epicycles; whereas if they had consulted nature, they would have found that while motion orderly and uniform is in a perfect circle, motion orderly but multiform, such as is found in many heavenly bodies, is in other lines; and deservedly does Gilbert laugh at this, saying that it is not probable nature would have formed wheels of one or two miles for instance in circuit, to carry a ball the size of a palm.1 For it seems that the body of a planet is no bigger, as compared with those circles which they invent for it to move in. The fifth is, that the stars are parts of their own orb fixed as it were by a nail. But this is very evidently a conceit of those who deal with mathematics not with nature, and fixing all their attention on the motion of bodies entirely forget their substances. For that fixation is a particular affection of compact and consistent things, which keep firm hold by reason of the pressure of their parts. But it is quite inconceivable, if it be transferred to soft or liquid bodies. The sixth is, that a star is the denser part of its own orb; whereas the stars are neither parts, nor denser. For they are not homogeneous with the air, differing only in degree, but they are quite heterogeneous and differ in substance; which