FIRST THOUGHTS ON THE GENERATION OF ANIMALS
Translation © George MacDonald Ross, 1975–1999
[518] As for how animals move, it must be observed that bodily motions depend on the direction animal spirits move in, and not on the speed at which they move, which is always constant; but only the smallest possible force is needed to make them move in one direction rather than another. To give an analogy, if a weight E is delicately balanced above the centre A, the smallest force that can be imagined is sufficient to make [519] the weight fall either towards B, or towards C. But suppose that a muscle D is attached to the weight: then the tiniest force will be enough to activate the muscle with great power, sometimes in one direction, sometimes in another. This analogy is by no means far-fetched, since the force of gravity is just as much a complex motion of the parts of corporeal matter as are animal spirits.[Click here if the illustration doesn’t appear automatically]
Go to Index to First Thoughts on the
Generation of Animals