Emerson describes successful people as “causationists” because they look for causes behind events rather than treating outcomes as matters of luck. In the surrounding passage, he argues that they assume events follow an intelligible order, with actions and conditions connected to consequences. This outlook encourages attention to what produces a result and what can be changed.

Within Power, the statement supports Emerson’s wider interest in practical effectiveness. People who understand relationships between effort, circumstance and outcome are better placed to act deliberately than those who rely on chance. His formulation is deliberately broad and does not mean that every success is fully controllable or that luck never matters. Rather, the quotation presents causal thinking as a useful habit: examine how results arise, identify the forces at work, and act on the assumption that outcomes usually have discoverable conditions behind them.

Full quotation

“All successful men have agreed in one thing—they were causationists. They believed that things went not by luck, but by law; that there was not a weak or a cracked link in the chain that joins the first and last of things.”