CHAP. VII.
Of Elements.
a 1.1 THe Element of Bodies is a simple Body, into which other Bodies are divided, in which it is either actually or potentially; as in flesh, wood, and the like; there is fire and earth potentially, for into these they are segregated; but actually they are not; for then should the flesh and wood bee segre∣gated.
Whereas every naturall Body hath a proper motion; motions are partly simple, partly mixt; the mixt proper to mixt bodies, the simple to simple; it is manifest that there are simple bodies, for there are simple motions; the circular proper to Heaven, the right to the Elements.
b 1.2 The Elements are not eternall; for they are dissolved with reciprocall mutations, and perish, and are mutually generated of one another.
c 1.3 The motive qualities of the Elements are gravity and levity. Heavy is that which is apt to be carried downwards to the Cen∣tre or midst of Heaven; light is that which is apt to be carried up∣wards towards the extremities of Heaven. These are either simple or comparative. Simply heavy is that which is below all, as the Earth; Simply light is that which is above, as all the fire; Com∣paratively heavy and light are those in which are both these; above some, below others; as Air and Water. From these have mixt things, gravity and levity; the heavy are carried downwards; to a definite medium; the light upwards to a definite extream, for nothing tends to infinite. Whence it followeth that two Ele∣ments are extreamly contrary, simply heavy, and simply light, Fire and Earth; which tend to contrary places. Betwixt these are two means, participating of the nature of each extream, Air and Water. Those Elements which are highest and lightest are most perfect, and have the nature of forms in respect of the infe∣riour, because these are contained by those; to be contained, is the property of matter, to contain, of form.
d 1.4 Hence it followeth that there are four kinds of particular se∣cond