Sex is one of many basic physical systems of the human body, one of the basic psychological systems of the mind, and one of the social dimensions upon which we develop our relationships. So, while it permeates our physical, mental and social well-being, it is not the only life energy, it is not the only psychological force occupying our mind and it is not the only social characteristic by which people are measured and held accountable. By examining each of these dimensions in more detail, starting with the physical dimension, we must conclude that Freud was too single-minded and simplistic in his understanding of what makes a human being `tick'.

The human body has numerous subsystems all controlled by the brain. These include the digestive, muscle, breathing, circulation and the reproductive systems. Our reproductive system is a combination of sex organs, which go through a predictable period of...