The affair of Nicholas Copernicus illustrated perfectly the need for the the two cornerstones of Western democracy: freedom of speech, and the independence of the people from control by the Church. Copernicus was an astronomer in an age where other astronomers applied more religious than scientific principles in their explanations of the sky’s events. His observations of the heavenly bodies’ movements put him squarely at odds with the Catholic Aristotelian view and he knew it: carefully releasing his treatise first as an anonymous pamphlet, and then as an extremely dense, technical work, to avoid the wrath of the Church.

On this day, March 5, in 1616, Copernicus’ de Revolutionibus (“On the Revolutions of Things”) was officially put by the Catholic Church on their index of forbidden works. The Church authorities agreed to release the book on the conditions that the astronomer strike the most offending parts from it, which Copernicus refused to do.

Copernicus lost the battle for his work — he spent most of his remaining life under house arrest — but he won the war. His view, backed by scientific calculations and observations, was found much more predictive of the observed changes in the sky, and eventually won out — but the Church defended its theory and prosecuted its critics every step of the way.