Good sense is of all things in the world the most equally distributed, for everybody thinks he is so well supplied with it, that even those most difficult to please in all other matters never desire more of it than they already possess.

This line comes from the opening of René Descartes’ 1637 Discours de la méthode (Discourse on the Method), published in Leiden as a preface to three scientific essays (Dioptrics, Meteors, and Geometry). Descartes begins with an ironic observation about “good sense” (bon sens)—the faculty of judging well—before arguing that the real problem is not a lack of reason but the misuse of it. The remark sets up his project: to propose a method for directing the mind so that reasoning becomes reliable, rather than merely assumed. It also reflects the early modern intellectual climate, in which appeals to common reason and method were central to challenges against scholastic authority.

Descartes wryly notes a universal human bias: nearly everyone believes they already possess sufficient “good sense,” even when they are demanding or dissatisfied in other areas. The point is not that reason is literally equal in all people, but that self-assessment of one’s rational capacity is famously overconfident. By starting here, Descartes clears space for his central claim: what distinguishes better thinkers is less an innate quantity of reason than the way it is guided—through method, clarity, and orderly inquiry. The line remains influential as an early statement of epistemic humility: confidence in one’s judgment is common, but warranted judgment requires disciplined procedures.