ABSTRACT
The desire for sex, as well as the decision to act upon that desire, stems from one of the most basic of all life needs, the largely unconscious need to persist beyond the moment, to cheat entropy and death by perpetuating some part of one's self into the future. The ultimate purpose of sex may be buried deep within the unconscious but not the desire. Sexually-related desires take a vast array of forms, animating directly or indirectly a large percentage of human choices and behavior. This chapter begins with a section on the evolutionary history of sex and follows with two additional sections highlighting the importance of Sexuality-related Well-Being Systems in human affairs. Virtually every plant or animal that people can see and are aware of practices sex of some kind. Sexual reproduction always involves the fusing of two unrelated cells to form a single new cell with similar but not identical genetic material to the parent cells.
