As M. A. Manzalaoui has noted, to choose book VII of John Gower's Confessio Amantis as a topic is to load oneself with the handicap of a subject most critics have found particularly dull. Furthermore, the passage from book VII describing the fifteen stars, stones and herbs is a subject most critics have entirely dismissed. With the exception of Patricia Eberle, those few scholars who have deigned to comment on the passage find it to be simply pedantic. While each of the previous six books of the Confessio focuses on one of the deadly sins, book VII is immediately a significant digression, for it does not discuss lechery, as expected, but describes ‘al that to a king belongeth’ (Confessio, VI, line 2413). The book is, in fact, a ‘mirror for princes’, a handbook of instruction for a young king; thus it elaborates the theme of kingship set out initially in the Prologue. Why, then, does Gower include a seemingly obscure and uninspiring passage on the fifteen stars, fifteen stones and fifteen herbs? How does such a passage fit into the poem's primary theme of kingship and secondary theme of love? By exploring the passage in light of the scientific treatises of the period, examining other references to stars, stones and herbs as they are found throughout the poem and determining the reception of the passage in the centuries immediately following Gower's death we begin to understand the importance such a presentation held for its author and his audience.

The theme of kingship and good governance is established in the Prologue and pervades the entire work. Book VII provides the greatest elaboration on this theme, resulting in the seeming divergence from the poem's principal narrative. It is presented as Aristotle's teaching to Alexander the Great and focuses on the two types of knowledge needed to be an effective ruler: theoretical knowledge, including theology, physics and mathematics, with a brief digression on the four elements, humours and parts of the world; and practical knowledge, including the five moral principles or points of policy – truth, liberality, justice, pity and charity.