Singleness of purpose is one of the chief essentials for success in life, no matter what may be one’s aim.

The saying frames “success” less as luck or raw talent than as disciplined concentration. “Singleness of purpose” implies choosing a clear aim and aligning time, habits, and resources toward it, resisting distraction and divided commitments. The second clause—“no matter what may be one’s aim”—universalizes the principle beyond business, suggesting that focus is a transferable virtue across professions and callings. Read in a Rockefeller context, it also reflects a managerial worldview: large outcomes are achieved by sustained attention to a defined objective, with competing priorities treated as threats to efficiency and progress.