Final answer:
The third section of 'In Memory of W.B. Yeats' focuses on the enduring power of poetry to preserve wisdom, compassion, and courage, influencing the moral and social discourse of society.
Step-by-step explanation:
The moral lesson in the third section of 'In Memory of W.B. Yeats' by W.H. Auden suggests a contemplation of the impact of a poet's work and the enduring nature of poetry amidst the transience of human life. The third section of 'In Memory of W.B. Yeats' focuses on the enduring power of poetry to preserve wisdom, compassion, and courage, influencing the moral and social discourse of society.
The poem dwells on how art, here specifically poetry, serves as a form of immortality as it outlasts the human condition, preserving ideas and values through time. This section hints at the importance of wisdom, compassion, and courage, themes that are perennial across cultures and ages, and how these qualities, as represented and evoked through poetry, contribute to the moral and social discourse of society.