The canonists who hold that the vasectomized man is impotent interpret the words of Sixtus V. to fit their opinion, although the vasectomized man has all the sexual potency of the normal man except that his spermatozoa are occluded. The potestas coeundi is not lost in any degree; neither he nor the woman is conscious of any change whatever. Only the microscope can tell that the spermatozoa are absent if the fact that he has been vasectomized is not told. Moreover, if vasectomy has been done by mere cutting without considerable resection, and especially if the vasa have been shut by ligation alone, no one can be certain that the occlusion is either certain or permanent. There is always doubt that the spermatozoa are present if the microscope is not used, and these canonists all disclaim the use of the microscope in such circumstances. The argument Ferreres uses, to the effect that the absence of spermatozoa is seriously injurious to the woman, is a supposition of his own arising from an erroneous notion of potency in the vasectomized. This absence is not injurious to her, but it is probably injurious to the vasectomized man because of the partial ejaculation. Onanism, which is different, is decidedly injurious to both the man and the woman.
Onanism, coitus interruptus, or withdrawal before ejaculation, which takes place extra vas, is intended to prevent impregnation. In the normal sexual act the male genital tract suddenly becomes congested with blood through nervous action of centres in the lumbar cord and the cerebrum. Cowper's and Littré's glands secret an alkaline fluid which neutralizes the acid urine in the urethra and thus prevents killing of the spermatozoa. Muscular peristaltic action presses out the spermatozoa and the secretions of the seminal vesicles and the prostate. When the act is normal there is a complete emptying of the tract of semen and of the blood engorgement; in coitus interruptus there is incomplete ejaculation and only partial deplethorization. The seminal vesicles remain distended, and this distention, with the congestion of the prostate, causes continual excitation of the sexual centres without relief. There is irritability and exhaustion of the centres, and this state brings on premature ejaculation and final impotentia coeundi. Other common effects are tenesmus of the urinary bladder, incontinence of urine, nocturnal pollutions, sexual neurasthenia, pain in the legs, over the eyes, and in almost any part of the body, general weakness, headache, vertigo, cardiac palpitation, neurotic dyspepsia, and a train of psychic symptoms which not seldom end in suicide.
In the woman there is the like blood engorgement and a pouring out of the secretions of Bartholin's and the other glands, but deplethorization takes place later in the woman than in the man, and for this reason the woman suffers more from coitus interruptus than the man does. In onanism, as in masturbation, after the diseased conditions have been established it is extremely difficult to induce the patient to resist the almost overwhelming irritation.
The canonists have interpreted the text of Sixtus V. to the effect that the eunuch is impotent precisely and solely because he cannot produce semen "elaboratum in testibus." No man produces semen elaboratum in testibus—more than 93 per cent. of the semen is produced entirely outside the testicle; nothing but the spermatozoa and two or three drops of a lubricating fluid are produced in the testicles. The eunuch really is impotent because the removal of the testicles and their nervous system so breaks the genital circuit, which consists of at least seventeen distinct parts, that erection is prevented, the formation of spermatozoa is impossible, the secretion of the essential vehicle of the sperm and of the fluids which render it fertile is cut off. The eunuch cannot penetrate and he cannot form any semen; he is impotent; the vasectomized man can penetrate, and he forms a semen which is sterile.
I think now the vasectomized man is really impotent for the reason that I think the mulier excisa is impotent, but he is not impotent because of the constitution of Sixtus V., which is not relevant at all to his case.
If the vasectomized man is impotent, the following cases are also impotent:
1. A man whose germ-cells have been destroyed by the action of the X-ray.
2. A man with double permanent occluding epididymitis.
3. A man whose vasa deferentia open into the ureters and not into the urethra.
4. A man whose vasa are shut by surgical operations for stone, or cysts of the prostate, or seminal vesicles.
5. A man whose seminal vesicles are shut by concretions, cysts, or tumors.
6. A man with bilateral cryptorchidism.
7. A man with a tuberculous condition of the testicles.
8. A man with absolute neurotic aspermia.
9. A man with congenital lack of development of the testicles or vasa.
Sterility in the male would exist only in advanced diabetes, general tuberculosis, senility, or in cases of absent or diseased prostate gland or seminal vesicles.
Here it is worth noting that since the copula must be natural, fit for generation in the natural manner, artificial impregnation by the use of instruments is immoral, and forbidden by a decree of the Holy Office, promulgated March 24, 1897. Artificial impregnation does not effect a copula which is by its nature proper to generation, but is an act contrary to nature, one from which generation does not follow in a natural manner, secundum communem speciem actus. It supposes deliberate pollution and semination outside the vagina, both of which actions are intrinsically evil.