Final answer:
Anchises tells Aeneas about the future of the Trojan line, offering insights from Stoic and Orphic philosophy and reflecting on the impermanence of empires, foretelling the Roman civilization's destiny tied to the Trojan lineage.
Step-by-step explanation:
According to what Anchises reveals to Aeneas about the future of the Trojan line, after Aeneas wonders why some souls would want to return to the upper world, Anchises provides a glimpse into Stoic cosmology and anthropology.
Anchises highlights the Orphic material, with references to the soul being imprisoned in the body, ideas inspired by Plato.
Furthermore, Anchises seems to reflect on the rise and fall of cities and empires, including Rome, providing a somber reminder of the impermanence of human achievements and linking it to the greater tapestry of history and the destiny that awaits the Trojan descendants.
The focus is on the lineage and its eventual role in founding the Roman civilization, which is a recurring theme throughout the story, encompassing notions of duty, destiny, and the eternal cycle of life and death.