What I must do is all that concerns me, not what the people think. This rule, equally arduous in actual and in intellectual life, may serve for the whole distinction between greatness and meanness.
Emerson argues that a person should focus on what they judge they ought to do rather than allowing public opinion to determine their conduct. The statement places duty and personal conviction above reputation, approval or fear of criticism. He acknowledges that this is difficult in both practical and intellectual life because social pressure can influence actions as well as beliefs.
Within Self-Reliance, the passage develops Emerson’s wider defence of independence and nonconformity. His contrast between “greatness” and “meanness” concerns the strength required to act according to considered principles rather than convenience or popularity. The claim does not imply that other people’s views should never be considered; instead, Emerson argues that they should not become the final authority. The quotation therefore presents moral and intellectual independence as the ability to judge one’s responsibilities for oneself and to follow them even when doing so attracts disapproval.