Hence the common centre of gravity of the earth, the sun, and all the planets, is the centre of the universe. This is because the sun, and all the planets, mutually gravitate one towards another, and are therefore, according to their powers of gravity, in perpetual agitation, as the Laws of Motion require, it is plain that their moveable centres can not be taken for the immovable centre of the world.

If that body were to be placed in the centre, towards which other bodies gravitate most, that privilege ought to be allowed to the sun; but since the sun itself is moved, a fixed point is to be chosen from which the be placed centre and from which it would recede yet least, and greater, and therefore less apt denser of the were sun body sun recedes of the less if the to be in moved. –> –>