When it comes to dealing with population growth, there are a number of misconceptions about the position of the Catholic Church. Official teaching during the twentieth century gradually moved toward the acceptance of limiting family size and endorsed the concept of responsible parenthood during the Second Vatican Council. One cannot, therefore, justifiably claim that the church is against birth control. It is an entirely different matter, however, when it comes to the practical question about how a couple might go about regulating fertility. Since the publication of Pope Paul VI’s 1968 encyclical, an intense controversy has taken place within the church about the use of artificial contraception. Behind that controversy lies an important methodological issue. For, the traditional teaching to which Paul VI returned in his letter was based upon the presumption that it is possible to morally judge a physical, material act without any consideration of the persons who performed that act, the circumstances within which it took place, or the reasons why the act was chosen. This behavioural approach to morality stands in some contrast to the way that other moral questions are dealt with. Inflicting pain or even taking a person’s life, for instance, can be justified for a good reason when one acts in a virtuous manner to instil discipline or safeguard justice. Until this methodological controversy is addressed, the problem of using artificial means to regulate fertility will not be resolved. A helpful key for solving the methodological ambiguities is to use moral language in a consistent and understandable manner.