In this essay I will ask if getting married and remaining married are rational things for a reflective person to do. I will limit my discussion to marriage within the western tradition. Most people in this tradition marry at some point in their lives. When they do, they are usually thought to be doing something worthwhile. Yet all too many marriages end in disappointment and divorce. So is it rational for us to choose to bind ourselves to another person in perpetuity in this way? To answer this question, I will begin by examining the sociobiological thesis which claims that human beings are gene-governed to pair bond. If this is correct, it might be thought that it explains the practice of marriage. However I will show that one implication of sociobiology is that, given this thesis, monogamous marriage goes against our natural inclinations; while pair bonding may be natural to us, exclusive pair bonding for life is not. I will go on to discuss the fact that monogamous heterosexual marriage is part of the traditional mores in western, Christian societies. The main reasons given in the past to support this tradition are that marriage provides a safe framework in which a couple's sexual needs can be met; it is the best setting for the procreation and rearing of children; and it provides couples with residential and economic advantages which are not open to non-marrieds. I show that there are good arguments for thinking that these reasons do not apply with quite the same force today. So we are still faced with our question: is it rational for a couple to choose to marry? There is, however, a more positive side to my account. For I will point out that even today when a couple choose to marry they believe that their marriage will be a good one and thereby both of them will lead happy lives. I will then identify some of the conditions which are necessary for the concept of 'a good marriage' to apply to a relationship and which are presumably conditions which guide most people's decisions in this matter.(Abstract shortened by ProQuest.).