Hazlitt isn't merely saying confidence helps you perform better—he's suggesting something more radical: that confidence actually *expands* what you're genuinely capable of, not just what you attempt. A violinist who believes herself inadequate won't develop the interpretive boldness that separates competence from artistry; her doubt literally constrains her capacity to grow. The insight cuts against the grain of modern self-help, which treats confidence as a tool you apply to fixed abilities, when Hazlitt saw it as the soil from which ability itself springs. This matters because it means your honest assessment of yourself becomes self-fulfilling in both directions—limiting yourself is as much a creative act as believing in yourself is.