On The Heavens   

number of the dimensions, one sort being continuous in one

direction, another in two, another in all. All magnitudes, then, which

are divisible are also continuous. Whether we can also say that

whatever is continuous is divisible does not yet, on our present

grounds, appear. One thing, however, is clear. We cannot pass beyond

body to a further kind, as we passed from length to surface, and

from surface to body. For if we could, it would cease to be true

that body is complete magnitude. We could pass beyond it only in

virtue of a defect in it; and that which is complete cannot be

defective, since it has being in every respect. Now bodies which are

classed as parts of the whole are each complete according to our

formula, since each possesses every dimension. But each is

determined relatively to that part which is next to it by contact, for

which reason each of them is in a sense many bodies. But the whole

of which they are parts must necessarily be complete, and thus, in

accordance with the meaning of the word, have being, not in some

respect only, but in every respect.



2



The question as to the nature of the whole, whether it is infinite

in size or limited in its total mass, is a matter for subsequent

inquiry. We will now speak of those parts of the whole which are

specifically distinct. Let us take this as our starting-point. All

natural bodies and magnitudes we hold to be, as such, capable of

locomotion; for nature, we say, is their principle of movement. But

all movement that is in place, all locomotion, as we term it, is

either straight or circular or a combination of these two, which are

the only simple movements. And the reason of this is that these two,

the straight and the circular line, are the only simple magnitudes.

Now revolution about the centre is circular motion, while the upward

and downward movements are in a straight line, 'upward' meaning motion