A wrongdoer is often a man who has left some thing undone, not always one who has done something.

The saying reframes moral failure as frequently a matter of omission rather than commission. In a Stoic framework, wrongdoing is not limited to overtly harmful acts; it also includes neglecting duties that reason and social nature impose—failing to help, to speak truth, to act justly, or to cultivate one’s own character. The line also encourages a more charitable, diagnostic view of others: what looks like vice may be a lapse in attention, courage, or understanding rather than deliberate malice. Ethically, it presses the reader to examine not only what they do, but what they fail to do, making responsibility active and continuous rather than merely prohibitive.