Meaning

The line makes a quietly devastating observation: the quality most people assume they possess is precisely the one that is rarest in practice. Common sense is supposed to be the most basic form of good judgment, requiring no special education or genius, yet Voltaire points out that clear, practical reasoning is actually quite uncommon. The irony is that everyone believes they have it, which is part of why it is so scarce.

Context

This line comes from Voltaire's Philosophical Dictionary, first published in 1764. That work is a collection of short alphabetical articles covering topics ranging from religion and politics to philosophy and human behavior, and it reflects Voltaire's characteristic method of making sharp observations in compact, memorable prose. The entry in which this remark appears is part of a broader examination of how people reason, or fail to reason, about everyday matters. The book was considered controversial at the time and was condemned and publicly burned in several places.

About the author

Voltaire was a French Enlightenment writer and thinker born in 1694. Over a long and productive career he wrote across an extraordinary range of forms, including drama, fiction, poetry, history, and philosophical essays. He was a committed advocate for reason, tolerance, and civil liberty, and he used wit as his primary weapon against superstition and oppression. His works remain central texts of the Enlightenment tradition, and he is still regarded as one of the great stylists of the French language.