The description of the seven planets in the Testament of Cresseid by the Scottish Chaucerian, Robert Henryson (c. 1425–c. 1500), is perhaps the most lively and arresting in English literature. Approximately one-third of the poem is devoted to the planets, and they play an essential role in the trial and punishment of Cresseid, who becomes a leper here and hereafter in the Troilus-Criseyde story. This note is an attempt to clear the way for the study of the origins and sources of the planet portraits and to shed some light on the competence of the poet.
By substituting astrological qualities for the mythological qualities of the ancient gods, Chaucer had pioneered and had made poetic capital of the astrological magic in which his age had come to believe. Henryson took full advantage of this fact. The Testament of Cresseid contains many elements of astrology: in the opening lines, the poet dates the poem by means of an astronomical periphrase in which he describes the Sun and Venus in opposition, a combination which signifies “A barren time … the Native impudent and bold in his wantonnesse and Lust, wholly occupied in scurvy and sordid actions, whereby he incurres great Infamy, Scandall and Disgrace,” and which sets the tone for the burden of the poem; the planets are ranked according to their astrological order, and Mercury is chosen speaker, a choice which accords with his influence over logic and debate; the choice of Saturn and Cynthia to deliver the verdict of leprosy is fitting, according to the astrological qualities of the humours, and the poet's treatment of the disease shows a detailed knowledge of astrological medicine.