Whether sperm comes forth from the entire body.
One inquires further into the principle of generation. And first, whether sperm comes forth from the entire body.
It seems so. For the generative power is given to every animal subject to corruption so that it may be preserved in one like itself, because it cannot be preserved in itself. But every body part is corruptible. Therefore, the generative power exists in every part. But generation occurs through the emission of sperm. Therefore, sperm comes from every part.
In addition, according to the Philosopher's argument, pleasure that occurs in one part is great, but is greater in more parts, and is therefore greatest in all parts. But the highest pleasure occurs in the emission of sperm. But this would not be the case unless sperm arose from all the parts. Therefore, etc.
Moreover, evacuations that relieve all the parts arise from all parts. But the evacuations of sperm relieve the entire body. Therefore, sperm proceeds from the entire body.
This is confirmed by the fact that the retention of sperm does not only afflict one part, but the entire body. This would not be the case unless it proceeded from the entire body.
The Philosopher says the opposite. And he proves it with this argument: that whatever proceeds from the entire body does not have a designated receptacle in the body, as is evident for sweat. But sperm has a designated receptacle. Therefore, it does not proceed from the entire body.
To this, one must reply that sperm can proceed from any given part of the body and, at the same time, from a designated part, because sperm is a superfluity of the last food. But the last food for any given member can have some superfluity. Therefore, sperm can be derived from any given member.
Moreover, it can arise from a designated part because nothing prevents one part from existing with perfect power and another one with imperfect power. Therefore, a perfect part can convert the last food totally into its nature leaving nothing superfluous behind. A part with imperfect power, however, can be hindered in this respect. Therefore, nothing prevents the sperm from being derived from one part and not from another.
On to the arguments. To the first, one must reply that it can be conceded. For in some way the arguments on both sides can be conceded, etc.
Whether the sperm is of the nature of parts or of some superfluity.
One inquires further whether sperm comes forth from every part or from some part by means of its dissolution or of derivation, and this is to inquire whether sperm is of the nature of parts or of some superfluity.
1. And it seems that sperm comes forth by means of dissolution. Because the body is weakened and enfeebled and dissolved by the sperm's emission. But this would only be because the sperm were something that is resolved or released from the parts. This is why, etc.
2. In addition, an accident does not exist without substance. But the power of every part exists in the sperm. Therefore, something of every part is also in the sperm. But this cannot be without the dissolution of the part. Therefore, etc.
3. In addition, the fetus resembles the parents in all its parts, because a cripple commonly generates a cripple and a leper generates a leper. But this would not be so if the sperm were not dissolved from each part. Therefore, etc.
The Philosopher says the opposite.
To this, one must reply that sperm is not something that exits from the parts by dissolution, because nothing is dissolved from the parts of the body without pain. But the ultimate pleasure occurs during the emission of sperm. Therefore, it does not come forth through the dissolution, or separation of a part, because if it did happen with the dissolution of the one containing it, then it would happen with pain.
Moreover, a great dissolution arises from a large body, and a small from a small. But animals with a large body have less sperm than animals with a small one. Therefore, sperm is not some dissolution.
In addition, if the sperm were something separated off from the nature of every part, since each part of flesh is flesh and each part of bone is bone and each part of nerve is nerve, then it would follow that sperm should be something composed of flesh, bone, and nerve. But every animal is composed of things like these. Sperm, then, would be a kind of animal. And the argument is the same for the woman's menstrual blood. Therefore, it would follow that any semen or sperm would be two animals. But one thing cannot be made from things like this. Therefore, sperm is not something that is separated off from individual parts.
Moreover, this is apparent by analogy in plants, because the seed [semen] is not something separated off from each part in them, because then any part could produce fruit, but fruit is generated from a certain superfluity residing in a certain part. Therefore, the same argument will apply to the animal semen.
1. On to the arguments. To the first, one must say that the emission of sperm is twofold: ordered and disordered. In an ordered emission nothing is emitted except the superfluity of the last food, and this does not weaken the body but rather it cleanses it. And the other emission is disordered, and such a one weakens the body, not because something is dissolved from the parts, but because the last food, which ought to be converted in the parts, is delegated to the seminal vessels, that is, the testicles.
2. To the second argument one must reply that the soul's power is emitted with the sperm. Nevertheless, this power exists in the spirit as in a subject. Therefore, there is a certain separating-off of the spirit with the sperm, but the spirit is not part of the body.
3. To the third argument one must reply that a likeness arises between the one generating and the one generated, not because the sperm is separated off from the parts of the one generating but because the sperm is a superfluity of the last food, which was in close potential to the body of the one generating, so that it may be converted into it. And this is why a flawed one generates a flawed one and a leper generates a leper, because the leper's last food, the superfluity of which is sperm, is corrupted in accordance with the corruption of his whole body. Therefore, the leper's sperm is corrupted and this is why there is a similar corruption in the fetus. The reason for the similarity of the one generated to the one generating will become evident in the sixteenth book of this work. Nevertheless, so far as it suffices for the premise, reason does not support the opposite view any more than it does the premise, because one who is mutilated often generates one who is not mutilated, and this is when the power of the one generating is capable of producing one that is perfect in species.