ment without starting it from that part's pivotaljoint which it does not move; and
370 The Literal Meaning of Genesis sockets ofthejoints to provide the thrust without which movement cannot begin; and it will discover that those parts that are being moved through local space are only moved by those which are stationary in place. A finger, you see, is not moved unless the hand is stationary, so that from its joint the finger may be moved as from a motionless pivot. In the same way when the whole hand is moved from the elbow joint, the elbow from the shoulder joint, the shoulder from the shoulder blade, the pivots of course remaining stationary to give thrust to the movement, the part being moved goes through a certain local space.
Likewise the foot has its joint in the ankle, which stays still for the foot to be moved; so too the shank's pivot is in the knee, the whole leg's in the hip. And there is no movement of any part of the body at all which the will can move that does not start from some pivot in a joint which a nod from the will first holds steady, so that the part to be moved can be started off with a thrust from the one that is not moving through local space. Finally, when you are walking, you cannot lift a foot unless the other one is firmly on the ground, carrying the whole weight of the body, until the one which is moving from the place it is being lifted from comes to rest in the place it is being lifted to, its pivotal joint remaining motionless throughout.
42. So now then, the will does not move any part of the body by local move ment without starting it from that part's pivotaljoint which it does not move; and yet both parts of the body, the one that is being moved and the one that remains stationary for the other to be moved, have their bodily quantities, occupying local space. How much more, then, does the soul, at whose beck and call, as it pleases, one of these parts will remain stationary to provide the necessary thrust for another to be moved—since the soul is not of a bodily nature, nor does it fill the body as its local space, like water filling a bottle or a sponge, but in wonderful ways it is mixed into the body it animates, and with its incorporeal nod, so to say, it powers or steers the body with a kind of concentration, not with any material engine48—how much less, I am saying, is this "nod" of its will the subject of local movement itself, in order to move the body locally, when it moves the whole body through its parts, and only moves some parts locally through others which it does not move locally!
48. He clearly lacks words to say how the incorporeal soul moves the body, that is, how it initiates movements, the mechanics of which he has been rather curiously setting forth. The phrase he uses which 1 have translated "with a kind of concentration, not with any material engine" is quadam intentione, non mole.