The man, then, would have sown the seed, and the woman received it, as need required, the generative organs being moved by the will, not excited by lust. For we move at will not only those members which are furnished with joints of solid bone, as the hands, feet, and fingers, but we move also at will those which are composed of slack and soft nerves: we can put them in motion, or stretch them out, or bend and twist them, or contract and stiffen them, as we do with the muscles of the mouth and face. The lungs, which are the very tenderest of the viscera except the brain, and are therefore carefully sheltered in the cavity of the chest, yet for all purposes of inhaling and exhaling the breath, and of uttering and modulating the voice, are obedient to the will when we breathe, exhale, speak, shout, or sing, just as the bellows obey the smith or the organist. I will not press the fact that some animals have a natural power to move a single spot of the skin with which their whole body is covered, if they have felt on it anything they wish to drive off,--a power so great, that by this shivering tremor of the skin they can not only shake off flies that have settled on them, but even spears that have fixed in their flesh. Man, it is true, has not this power; but is this any reason for supposing that God could not give it to such creatures as He wished to possess it? And therefore man himself also might very well have enjoyed absolute power over his members had he not forfeited it by his disobedience; for it was not difficult for God to form him so that what is now moved in his body only by lust should have been moved only at will.