In his introduction LaFleur suggests that "medieval Japan" be defined as "that epoch during which the basic intellectual problems, the most authoritative texts and resources, and the central symbols were all Buddhist". (He doesn't, however, draw any parallels with Christianity in medieval Europe.) Japanese Buddhist writings were didactic, "argumentative and insistent" at the beginning and end of the period, when they were facing rival ideological systems, and more subtle in between. They exhibit an ambivalence about the Buddhist symbolic tradition and "a strong conflation of the religious and literary dimensions of human experience".
The first work considered is the early Heian Nihon ryōi-ki, which presents bluntly didactic explanations of anomalies ("miracles") using the Buddhist system of karma and the cycle of rokudo. (Here LaFleur attempts, somewhat oddly, to provide medical/scientific explanations for the events described.) This illustrates the threat of despair and four approaches to escaping the cycles: through the infiltration of bodhisattvas such as Kannon and Jizō, by transcending them, as in the "Western Paradise" of Pure Land Buddhism, by postulating their interpenetration, as in Tendai, or through a ludic or game-playing approach, as in Zen.
Turning to mujō or impermanence, LaFleur analyses the tropes/topoi of the hermit's hut and the traveller's inn, in works by Chomei and others. In some ways these were opposed, but (in a kind of structuralist analysis) both can be contrasted with settled people in stable houses, the first with impermanent housing, the second with moving people.
"Japanese literature shaped by Confucian values or even pre-Buddhist values may celebrate the overwhelmingly attractive sense of security provided by one's own domicile, but an orthodox Buddhist position would be that both inn and hermitage are more closely in harmony with the real structure of the universe."
Looking at "depth" in poetry and the aesthetic of yūgen, LaFleur focuses on Tendai Buddhism, and the Lotus Sutra in particular, and its use in a treatise on poetry by Fujiwara Shunzei. This is radically non-dualist and non-Platonist: parables are not just pointers to an underlying reality, but attempt a breakdown of the divide between observer and observed, between phenomena and interpretation.
LaFleur describes the role of the figure of the Buddhist layman Vimalakirti in the Mahayana tradition, leading up to Chomei's Hōjō-ki.
"The Buddhism in it ... has been developed and refined through centuries of Indian and Chinese Mahayanist thinking about the relationship of Buddhist ideals to worldly realities, of nirvana to samsara, and of religious to mundane vocations. ... it is a clear example of a type of literature that I have called the high medieval in Japanese history."
Analysing the treatises on nō drama written by Zeami Motokiyo, LaFleur looks at correspondences between the Buddhist scale of existence and the different categories of nō. Zeami's works were guides for actors and emphasize "the training of a nō actor as a religious discipline". The moral challenge in nō is not in the conflict of the protagonist with an antagonist, but in alternative visions of the situation and fate of the protagonist.
"On the surface, what happens to Buddhism in kyōgen seems fairly clear: it is mercilessly satirized and lampooned." LaFleur analyses kyōgen as a popular genre, written for people who had moved up in the world, elevating pragmatism and "this worldly" success over theory and withdrawal from the world. But kyōgen was gradually stripped of its strongest satire and ritualised as a symbolic inversion contained by nō.
LaFleur concludes with an analysis of a short passage from Basho's Narrow Road to the Far North, in which Basho writes down thoughts on the etymology of the Chinese character for "chestnut". This links to the 8th century seer Gyogi and the 12th century poet Saigyo, providing a trajectory which LaFleur uses to highlight the gradual rather than radical introduction of "modernity" in Japanese thought.
There are references in The Karma of Words to Kuhn, Foucault, and so forth — the theorists most trendy in the early 1980s — but it makes no attempt to impose any theoretical, rather than historical, framework. It proceeds rather by the close reading of texts in their intellectual contexts. In this it goes into quite some density of detail, but it is never dull and is presented in such a way that it can be enjoyed by those without much knowledge either of Buddhist ideology or Japanese literature. (Though some experience with theology and literary criticism would help.) The Karma of Words is a book that could open up whole new worlds.