Exertion

A political activist wants to change an unfair law. He writes letters, gives speeches, and organizes peaceful marches. He pours all his energy into the cause, day after day. But the law does not change immediately. Despite all his effort, success is not guaranteed. He is applying force, but the outcome remains uncertain. What is the activist putting into his work? He is putting exertion into his work.

Exertion means the application of effort or pressure, without guaranteeing any outcome. First‑cause, by contrast, means the original source that starts a chain of causation, with nothing before it. So, exertion focuses on the active pushing or trying, regardless of success. First‑cause focuses on the ultimate origin of all causation. In other words, exertion is the effort you put in now, which may or may not lead to a result; first‑cause is the very first spark that sets everything in motion, with nothing causing it.