The difficult part in an argument is not to defend one's opinion but rather to know it.

Maurois’s aphorism shifts the focus of debate from rhetorical skill to intellectual self-knowledge. Many people can marshal reasons, authorities, or clever retorts to “defend” a position, but the harder task is to determine what one truly thinks—separating inherited slogans, momentary emotions, and social pressures from considered judgment. The line implies that argument should begin with clarification: defining terms, examining assumptions, and testing one’s own reasons before engaging an opponent. It also carries a moral warning against performative disputation, where winning replaces understanding. In this view, the most serious weakness in argument is not lack of ammunition but lack of genuine conviction grounded in reflection.