Mathematics Is The Language In Which

Galileo Galilei wrote this in The Assayer (Il Saggiatore, 1623), a polemical work attacking the Jesuit astronomer Orazio Grassi's theory of comets. The surrounding passage argues that natural philosophy must be read in the "book of nature," which is "written in the language of mathematics." The image became one of the most quoted statements in the philosophy of science and is central to the idea that physical reality has a mathematical structure.