ABSTRACT
Inasmuch as Celtic scholars have tended to feel that the Four Branches of the Mabinogi are devoid of both theme and structure, this article’s title is not as innocuous as it might seem. While the stories of the Mabinogion developed over an extended period of time, a single redactor appears to have taken the Four Branches in hand; however, the extent to which he refashioned them is a matter for conjecture. In structure Manawydan Son of Llyr is by far the simplest of the Four Branches—indeed its peculiar opening suggests that it may have replaced an earlier story. The theme generated by the structure should now be apparent. In a sense, the structure is the theme; for, as alternating tales balance and sequences parallel each other, so the world of the Four Branches is an ideally just one in which good begets good, evil.
