His work "After Virtue" MacIntyre begins with a review of the state of modern moral theory and moral and practical life. According to MacIntyre, the distinctive feature of this state is that both the language of modern morality and modern practices of moral life are in complete disarray. As MacIntyre emphasizes, contemporary moral controversies and disagreements do not lead us to the adoption of any rationally substantiated point of view, and the moral arguments used in them are conceptually incommensurable and therefore do not contribute to the development of a common moral position. In order to make the formulation of the question of the character of the contemporary moral situation more evident, MacIntyre proposes to imagine an imaginary world, from which, after a global cataclysm, natural sciences and all the practices of research and education associated with them have disappeared.
If, some time later, enlightened people attempted to revive science, they would have to face a situation where everything that the new scientists did and said would correspond to certain canons of consistency and coherence, but a context that could give meaning to all their actions, was lost, and, in all likelihood, irrevocably.
As MacIntyre notes, in such a culture, people would use expressions such as "neutrinos", "mass", "gravity", "atomic weight" and others in a systematic and interrelated way, reminiscent of how these expressions were used in those times when scientific knowledge has not yet been lost. However, most of the beliefs implied by the use of these expressions would be lost, and their application would be largely arbitrary, capable of leading us only to a dead end.
According to MacIntyre's plan, a similar example with an imaginary world populated by fictitious pseudoscientists and real real scientists is designed to help clarify the current state of moral theory and moral practice. In his opinion, it is determined by the fact that in the past there was a moral disaster that remained unnoticed for us, as a result of which we are using moral concepts torn from their own context and therefore devoid of authentic meaning.