It is the greatest of all mistakes to do nothing because you can only do little - do what you can.

The aphorism targets a common rationalization for inaction: the belief that small efforts are pointless against large needs. Smith reframes this as a “greatest mistake,” arguing that limited capacity does not negate responsibility. The imperative “do what you can” shifts attention from outcomes beyond one’s control to agency within one’s control, making moral action incremental and cumulative. Its enduring appeal lies in its practicality: it validates modest contributions while condemning the self-exculpating perfectionism that waits for ideal conditions, complete solutions, or heroic scale before beginning.