Essential Reading for Men's Health: The System of Sex Science and the Analysis of the Nature of Sexual Desire

What disciplines does sex science encompass?

Practice in human sexual life demonstrates that sex, sexual desire, and sexual behavior, as complex life phenomena, should be objects of scientific research. Sexology, as a science, is a newly emerging interdisciplinary field that studies the general laws governing the formation, development, and differences in human sex, sexual desire, and sexual behavior. Due to the specific nature of its research objects, it inevitably involves many aspects of both natural and social sciences, thus possessing attributes of both.

The study of sex science is very broad, mainly including the following parts:

1. The history of sexual evolution;

2. Sexogenesis and sexual development;

3. Sexual anatomy and sexual physiology;

4. Sexual medicine and sex therapy;

5. Sexual psychology;

6. Sexual behavior;

7. Sexual sociology;

8. Sexual ethics;

9. Sexual criminology;

10. Sexual law;

11. Sexual education;

12. Sexual aesthetics;

13. Sexual philosophy;

In addition, there are disciplines such as sexual folklore, sexual anthropology, and the emerging field of sexual love studies. In the past, people equated sex science with medicine, which is a one-sided understanding of sex science. Currently, research on sex science abroad has expanded to almost all humanities disciplines.

What is sexual desire? Why do people have sexual desire?

Sexual desire, also known as sexual motivation or sexual drive, is the desire for sexual behavior. Specifically, sexual desire has two meanings: the desire for physical contact between opposite sexes and the desire for sexual intercourse under certain stimuli. When sexual desire persists to a certain degree, physiological changes occur. In men, this manifests as penile erection and the discharge of fluid from the urethral opening from the paraurethral glands; in women, it manifests as clitoral erection and the discharge of fluid from the vaginal walls. Therefore, sexual desire is a complex biological phenomenon, a shared physiological and psychological experience of all humans, a subtle change originating deep within the brain.

Human sexual desire is an inevitable physiological and psychological phenomenon in heterosexual relationships, and also an instinct inherent in humankind for the continuation and development of the species. Thus, the ancients said, "Food and sex are the greatest desires of humankind" (The Book of Rites), and "Food and sex are human nature" (Mencius). It is evident that sexual desire, like appetite, is human nature; only with sexual desire can there be sexual behavior. Seeing the beautiful face, charming figure, and loving gaze of a beloved person of the opposite sex can generate sexual desire. Sometimes, photographs, sounds, and even smells can also arouse sexual desire.

The information received through sight, hearing, smell, and touch is transmitted to the brain via nerves, exciting the sexual center and generating sexual desire.

Sexual desire is also an instinctive impulse to satisfy the body's sexual needs. In Traditional Chinese Medicine, it is called "qingyu" or "yinyu." Sexual desire is a somewhat vague concept, more easily understood than explained in words; it's a phenomenon that most people seem to intuitively perceive, but is not easily explained scientifically. In daily life and literature, the term "sexual desire" is often expressed using terms such as sexual interest, sexual desire, sexual demands, lust, qingyu, lust, love, and sexual love.

Sexual desire can be subdivided into two forms: the desire for contact and the desire for release (also known as the desire for intercourse), or divided into psychological and spiritual needs (qingyu) and physiological and sensory needs (lust).

The desire for contact refers to the craving for contact with the opposite sex, from kissing, hugging, and caressing to close physical contact, and even direct contact of the genitals. The cumulative effect of contact can enhance the intensity of sexual response until orgasm. Women generally have a stronger desire for contact than men.

The urge to release tension, also known as the urge to ejaculate, arises in sexually mature men as their testes and accessory glands continuously produce sperm and semen. The vas deferens becomes full of semen, increasing sexual sensitivity and creating a special sexual tension, resulting in a strong desire to ejaculate. In sexually mature women, due to the cyclical changes in the ovaries and increased secretion of endocrine hormones, sexual sensitivity also increases. Increased secretion from the vestibular glands and vagina also leads to a stronger sexual desire. While the urge to ejaculate is less pronounced in women than in men, it often exhibits cyclical changes, what Traditional Chinese Medicine calls the "Yin Yun period," during which women often experience an unbearable urge to intercourse. Functionally, ejaculation is the ultimate goal of sexual behavior.

Human sexual desire is often influenced by physiological, psychological, and social factors. Changes in libido often manifest as hypersexuality, hyposexuality, decreased libido, abnormal libido, or paraphilia.

The intensity of libido depends on three factors: the intensity and effectiveness of external sexual stimulation; the sensitivity to sexual stimulation; and the intensity of the sexual physiological response.

The standard for judging moderate libido is the ability to "release" and "control," maintaining a balance between activity and rest, which promotes physical and mental health.

Libido is controlled by the hypothalamus in the central nervous system and endocrine system of the brain. The hypothalamus, through the pituitary gland, "commands" the gonads (such as the ovaries and testes) to secrete sex hormones that enter the bloodstream, thus producing a sexual response. Of course, libido is also influenced by psychological and social factors. Therefore, there is a great deal of individual variation in libido. Even for the same person, the level of libido varies with age, health, living conditions and environment, work schedule, marital relationship, emotional state, and sexual experience, making a unified standard difficult to establish.