Measure What Is Measurable And Make

This methodological maxim is attributed to Galileo Galilei but does not appear verbatim in his documented works. The spirit of the phrase accurately reflects Galileo's practice: he consistently sought to quantify natural phenomena and expressed frustration with qualitative Aristotelian descriptions. A closely related statement appears in his The Assayer (1623). Whether the precise formulation is his, the principle captures the essence of the scientific revolution he helped initiate.