A Canticle for Leibowitz Imagery
MacIntyre opens After Virtue with the scenario from the science fiction novel A Canticle for Leibowitz. In it, the foundations of science have eroded away, and all that is left for the people of the post-apocalyptic earth is fragments of advanced scientific documents that appear mystical and religious to them. He uses this scenario as a metaphorical allegory for the current state of morality in modernity, so the imagery is recurrent and prevalent.
Polynesian Imagery
MacIntyre uses another metaphorical example, this one from real life. King Kamehameha II abolished the Polynesian taboo rules that had been upheld for centuries, but he encountered very little resistance because the people had lost all sense of meaning and reference for these rules. This image is a recurring one throughout the book, and this Polynesian imagery, while making the book a little more colorful, also brings a sense of specificity to this highly theoretical work.
Veneer Imagery
MacIntyre argues that the current perceptions of morality are actually just façades; the true foundation of morality eroded long ago with the advent of the Enlightenment in Europe. The theories of morality that we see today, therefore, are just remnants of ancient philosophies that we no longer understand. This imagery of the moral veneer is a predominant one throughout the book, and an immensely sobering one.
The Dead Fish
MacIntyre uses an example in Chapter 8 to suggest the possibility that the perceived problem with social science is not actually a problem at all, using the image of a dead fish. This particular dead fish is part of an anecdote wherein King Charles II of England poses a scientific question to his Royal Society: why does a dead fish weigh more than a live fish? Various theories were proposed, and then Charles announced that the problem was actually nonexistent: a dead fish doesn't actually weigh more. This image is a memorable one, providing a reminder that some perceived problems might not actually be so.