I want to begin with a picture I do not accept, and I will try to explain why I do not accept it and what I want to put in its place. It goes like this—‘Sex is first of all a matter of fulfilment... it is an appetite which must be satisfied one way or another; sexual desire is something implanted in us by nature and nature’s purpose is the maintenance of the race. But nature with her usual lavish hand has given us far more sexual desire than is really necessary, just as she makes far more cod’s eggs than are really necessary to keep up the population of cod. Because our sexual desires are stronger and more frequent than is really necessary we are led into various kinds of competition and violence, disorder and war. In order to regulate this stimulation man has invented the institution of marriage. Marriage is rather like the institution of private property to which indeed it is closely related. Men have an appetite for possessions greater than is really necessary and to regulate this appetite we grow hedges round bits of land and say to a man “Go in there and own away to your heart’s content but don’t come over the hedge into my bit of land”. Private property means that a man may perhaps have less than he would like, but what he has is secure’. Marriage according to this picture is a fence around the sexual appetite just as the hedge is a fence around the appetite for possessions. Marriage is a limit set on sexual activity for the sake of other people.