While this prolegomenon will introduce a traditional problem in Catullan scholarship, it will not be a comprehensive survey of the scholarship or a balanced account of all of its major trends and approaches. Instead, it sets out what has proved to be the most fruitful way of searching for authorial design in the Catullan poems and explains the interpretive progress that has been achieved by application of this approach. Other approaches are certainly possible, and this one may, if taken alone, ultimately prove inadequate to the problem it confronts. But it has produced nearly all of the progress made to date in the area of Catullan arrangement.