A Latin word-ending meaning “requiring to be done” or “worthy of being done.” Hence, liber legendus est, the book is worth reading. The suffix gives rise to such English words as agenda (that requiring to be acted upon) and corrigendum (an error needing correction). Diamond transforms the suffix into an independent noun, meaning “a task (or activity) that is required to be done,” and contrasts with a “must,”a task we feel compelled to do. Approaching a task as an endum rather than a must raises our Life Energy and encourages us to perform it as an Aspiration*.

Timeline: Diamond developed the concept c. 1996.

Commentary: Diamond originally used the concept as a positive approach to working with emotional or physical problems. If we approach such activity as an endum rather than must, both the experience of doing the task and the results are likely to be more positive. More recently he has also used the term in regard with Li*, one of Four Cardinal Virtues of Mencius*. Usually translated as propriety or proper ritual, Diamond regards Li effectively as an endum.