Definition
Rationality is the capacity to see things as they are rather than as fear, desire, or vanity would have them appear. For Robert Greene it is not coldness or the absence of feeling — it is the discipline of preventing emotion and bias from quietly governing judgment.
Greene treats rationality as a skill, not a fixed trait. It can be weakened by impatience and ego, and it can be strengthened by deliberate practice — much like any other ability.
Why it matters
How it works
Greene describes rationality as an ongoing internal practice. The first step is recognizing one's own susceptibility — accepting that emotion and bias affect everyone, oneself included. The second is creating distance: pausing before important decisions, examining the feeling behind a strong opinion, and testing conclusions against evidence rather than preference.
Over time these habits build a steadier relationship to reality. Rationality does not eliminate emotion, which carries real information; it ensures that reason, rather than reaction, has the final word on consequential choices. Greene presents it as a cornerstone of both wise action and lasting self-development.