Semen is the surplus that arises after the fourth digestion, which is carried out during the distribution of nutrition in the organs, and seeps through the blood vessels, having completely undergone the third digestion. The seed is part of the newly condensed innate moisture, which feeds the main organs - veins, arteries and the like. Sometimes a large amount of this moisture is dispersed in the blood vessels; Having previously undergone the fourth digestion, it remains there so that the blood vessels feed on it, or it enters organs similar to the blood vessels, and they feed on it without the need to significantly change it; As a result, the seed passes from the vessels to these organs. According to Galen and other doctors, both man and woman have a seed, which both call mani, but not due to the actual commonality of the name, but by agreement; each of both types of seed simultaneously has two abilities - the ability to form and the ability to perceive form, but the male seed, with the permission of Allah, is more powerful in terms of the force from which the formative principle comes, and the female one is more powerful in terms of the force that is the source of the beginning, the form of the perceiver. The male seed, according to doctors, is poured into the horn of the uterus, and the mouth of the uterus absorbs it, strongly drawing it into itself, and the female seed is poured through the canals and blood vessels from inside the uterus to the place of conception.
As for scientists and philosophers, as a result of studying their teaching, it turns out that the male seed has only a formative principle, and the female seed has only a principle that perceives form when performing the work related to it. The formative force of the male seed, when forming, strives to create the likeness of the one from whom it was separated, unless there is hindrance or obstacle to this, and the force of the female seed, which perceives the form, strives, when perceiving the form, to find it similar to the one from whom it comes. The name mani, say philosophers, when it is attributed to one or another seed, is attached to them due to the commonality of the name, and not the meaning, unless an impossible general meaning is invented according to which this thing is called mani. As for the meaning according to which mani is the name given to the semen ejaculated by a man, the semen ejaculated by a woman is not mani. And indeed, the male seed is hot, mature, thick, and the female seed is something like the blood of menstrual purifications, which is slightly ripened or slightly changed and is not as far from blood matter as the male seed. Therefore, the ancient philosopher calls the female semen the blood of menstruation. Philosophers assert that the male seed, when mixed with the female, acts with a special power and its corporeality does not have much participation in the formation of the substance of the baby's body, for this ability comes from the female seed and from the blood of menstruation. On the contrary, the most important task of the male semen is to create the substance of the baby's pneuma, and the male semen is only like rennet, which acts on milk. And the female seed is the basis of the substance of the baby’s body; and each seed abundantly endows it with that which produces fresh hot blood containing pneuma. As for knowing which of the two teachings is correct, this relates to natural science and ignorance of this does not harm the doctor. We have explained how this is dealt with in our main books.
Hippocrates speaks about the seed, the meaning of which is that most of the matter of the seed comes from the brain; it descends through two blood vessels passing behind the ears; and therefore bleeding from them stops the production of offspring and causes infertility; the blood that forms the seed is milky white. These vessels reach the spinal cord, so as not to move too far from the brain and what is similar to it, for then the nature of this blood will change and it will undergo a transformation; on the contrary, these vessels pass to the spinal cord, then to the kidneys and then to the vessels that go to the testes. Galen did not know whether cutting these vessels caused sterility or not.
I believe that the seed does not necessarily have to come only from the brain, although its leaven is from the brain, and what Hippocrates says about those two vessels is correct. On the contrary, the seed must have a source in every predominant organ, and the other organs must also exude something into these principal organs of propagation; because of. This creates a hereditary similarity and as a result, an insufficient organ is born from an insufficient organ. This does not happen until the vessels dilate with puberty and lust rises to full maturity. Sometimes the seed is driven out by the winds that mix with it, and it must come out before the winds come out.