Book 3
3
Further, our theory can, I think, demonstrate both together; for seeing that they succeed each other, and that the one keeps giving place to the other according as utility demands, it seems not unreasonable to accept a common demonstration also for both. Thus it is the work of the retentive faculty to make the uterus contract upon the foetus at every point, so that, naturally enough, when the midwives palpate it, the os is found to be closed, whilst the pregnant women themselves, during the first days — and particularly on that on which conception takes place — experience a sensation as if the uterus were moving and contracting upon itself. Now, if both of these things occur — if the os closes apart from inflammation or any other disease, and if this is accompanied by a feeling of movement in the uterus — then the women believe that they have received the semen which comes from the male, and that they are retaining it.
