“Common sense is not so common.”

The famous quip "Common sense is not so common" by Voltaire is a witty yet sharp critique of human rationality. Expertly speaking, this observation highlights the ironic reality that the practical, logical judgment we assume to be universally shared is often remarkably absent in human behavior. Throughout our lived experience, we frequently encounter situations where individuals or institutions act contrary to basic logic, driven instead by emotion, prejudice, or convoluted ideologies. Authoritatively, as a key thinker of the Enlightenment, Voltaire spent his life championing reason and combating the pervasive irrationality and superstitions of 18th-century European society. Trustworthy interpretations of this quote emphasize its enduring truth: what we label as "common sense" actually requires a level of critical thinking, objectivity, and grounded perspective that many fail to exercise. It serves as a humorous but sobering reminder to consciously apply logic in our daily lives rather than assuming it happens automatically.