This article aims at proposing a solution to one of the well-known textual cruces in Lucretius’ De rerum natura. After a brief survey of the suggested emendations, the author will shed some fresh light on Manning's gratus, which recent editors have curiously neglected. The idea that the old man should retire from life with thanks is not uncommon among classical writers. In addition, parallel expressions are also found in Epicurus’ own words. This article concludes that gratus is what we would (...) expect in the last line of Nature's admonition in De rerum natura and, therefore, the most probable emendation. (shrink)