Insight is Bernard Lonergan's masterwork. It aim is nothing less than insight into insight itself, a comprehensive view of knowledge and understanding, and to state what one needs to understand and how one proceeds to understand it. In Lonergan's own words: 'Thoroughly understand what it is to understand, and not only will you understand the broad lines of all there is to be understood but also you will possess a fixed base, and invariant pattern, opening upon all further developments of understanding.' The editors of the Collected Works of Bernard Lonergan have established the definitive text for Insight after examining all the variant forms in Lonergan's manuscripts and papers. The volume includes introductory material and annotation to enable the reader to appreciate more fully this challenging work.