B. In Man

428. - 1. Sexual instinct is also present in man, but is less defined. For a twofold instinct can be distinguished: one, strictly so called, which is borne immediately toward carnal pleasure to be obtained through copulation: it moves body toward body in order to obtain venereal pleasure. The other moves person toward person, or seeks a person of the other sex because of secondary sexual characters, that is, because of the psychic and somatic qualities of the other sex, whose company is thereby rendered agreeable. But this interest in the person remotely disposes one toward venereal pleasure. Together with the person, the body is near; familiar association soon excites the carnal appetite itself. All these things have been wisely ordered so that matrimony among men would truly be not a mere conjunction of bodies, but would dispose and lead toward bodily enjoyment through a more universal union.

429. - On sexual instinct strictly so called. The stimuli of sexual instinct strictly so called are distinguished into normal or customary stimuli common to men, and abnormal stimuli which are proper to certain persons. They are further specific if they have almost no other use than to actualize sexual instinct; while those are called common which also possess some other utility.

Normal and specific stimuli are psychic or nonpsychic, that is, merely material. The latter affect the nerve centers by a chemical influence and operate independently of every consciousness of the subject: thus aphrodisiac drugs, and especially the "hormones" secreted internally, to whose influence nocturnal pollution seems chiefly to be ascribed. Some add the very pressure (la pression) of a gland which abounds in elements to be excreted.

A psychic stimulus does not move unless it is known. In order that it exert its power, besides an object suitable for exciting the appetite, or savory, and that object known, there is required in the subject an aptitude for undergoing that incitation, and then for acting upon the object, or for being acted upon, which we can call sensibility: it is called "receptivity and reactivity."

These subjective aptitudes vary considerably. There are some who are affected in no way by a whole particular class of stimuli, while for others the stimulus must be furnished with certain peculiar notes: some are excited by nudity, others by colors; some, besides nudity, require definite forms of the body from which others shrink. Stimuli, therefore, are relative, yet not to such a degree that there are none to which a common excitatory power can be assigned, which, before experience, is to be presumed capable of being effective. Such are, when perceived by external sensation or represented internally, the sexual functions, the sexual parts, a certain nudity of the body, and the acts preliminary to copulation.

2. Once the stimuli have been received, there follows a certain affective state, sufficiently complex, composed of the agreeable elements of sexual sensations and of the disagreeable elements of the excited and distended organ and of the unsatisfied venereal appetite: the excited and distended organ physiologically, and the unsatisfied appetite psychologically, induce an affective state in which discomfort and unpleasantness prevail.

3. Hence there arises an appetite for full satiety, which will be obtained when the agreeable affections are completed and the others removed. To this end, through instinct they appear to the phantasy, and through experience to reason, as manipulations to be performed about the sexual organs, especially those of the other sex; the subject is vehemently impelled to perform them (the appetite of manipulation). Excitation then increases with the addition of new stimuli, and the akme, or apex of excitation, is reached. Then the greatest pleasure of the lower order is obtained, and at the same time, with the outpouring of semen or quasi-semen, the orgasm is resolved, by which name is meant the whole process of the greatest carnal commotion, consisting of sensations, affections, and physiological changes. But the natural impulse to remove the tension of the organs is called the appetite of detumescence: it is satisfied in the orgasm itself.

430. - 4. You should therefore observe that, as such, venereal instinct is borne not toward procreating offspring but toward experiencing one's own pleasure.

But the nexus between stimuli, sensations, affections, appetite, and the impulse toward execution or exterior acts is not from human choice but from a natural connection and the instinct's innate associations.

5. Venereal instinct in man is variously subject to the command of the rational faculties. Led by intellect and will, which, because of the unity of the human composite, are also inclined toward seeking these things, man can deliberately seek sexual stimuli, retain them, increase them even artificially, preserve them longer, and excite himself in unusual ways for which there is no desire in brute animals. For man, unlike a brute animal, at the same time senses how unequal even complete carnal satisfaction is to procuring happiness. Therefore, the stimulus to perceive the sensation is received in him with the desire of increasing satiety itself. And he can also deny assent to the stimuli and to the affections themselves, call the mind away to higher things, diminish the efficacy of the stimuli by antecedent thought, and deliberately flee occasions of excitation.

431. - On sexual instinct broadly so called. Persons of different sex can also be bound together by a noble friendship: thus the strictly sexual consideration is ordinarily very far removed from the affection of children toward both parents and of parents toward offspring. But when the other sex is formally sought, then love founded upon sexual characters is necessarily, at least in part, sensual. (And even into a noble affection toward a person of the other sex who is not closely related by blood, something sensual easily enters.)

Sexual instinct broadly so called also becomes active with the aid of stimuli which are chiefly psychic (which do not act unless known).

These stimuli induce an affective state similar to that which exists in venereal instinct. There is agreeableness if the person toward whom the subject is borne is present and place is given to the desired association. If either one is missed, an affection of tension and discomfort will prevail, with an inclination toward seeking full satisfaction. A more vehement affection brings about physiological changes, sensations with connected affections; not, however, in the genital organs, at least of itself. But if it begins to pass into carnal appetite, changes will at once be present in these organs. Yet you should observe that this carnal propensity can be involuntary and repudiated.

The appetite tends, as we have said, toward obtaining a common and total affection of agreeableness; toward retaining and completing it, if it is present. It therefore impels toward interior and exterior acts by which union with the beloved person is perceived. But the more the proximity of persons becomes a proximity of bodies, the more attention is directed toward typical bodily qualities (the secondary criteria of sex), and the more the union between persons manifests itself by bodily signs such as kisses, prolonged embraces, caresses, etc. Conversely, the more one withdraws from carnal instinct, the more attention is given to psychic qualities, and bodily signs of familiarity are more or less neglected.

These things prepare the way for not a few prudent counsels.

Nothing special need be added concerning the action of the higher faculties. When the matter advises it, these can prudently prevent the propensity from becoming carnal; prevent carnal movements which may happen to arise from being accepted; lead persons to renounce every satisfaction of the senses; and prudently break off the association itself when it is not very useful.