Man — a reasoning rather than a reasonable animal.

The aphorism draws a sharp distinction between the capacity to produce reasons and the disposition to be guided by reason. Calling man “reasoning” suggests ingenuity in argumentation—often in service of passion, interest, or faction—while “reasonable” implies restraint, fairness, and a willingness to revise one’s views. In political terms, the thought warns that public debate may be rich in rationalizations without yielding rational outcomes, underscoring the need for institutions that channel self-interest and temper volatility. As a general maxim, it is a critique of human rationality: people can argue persuasively, but that does not guarantee wise judgment or reasonable conduct.