How did Copernicus
How did Copernicus’ theory of the heavens invalidate Aristotle, and what were its implications on the common sense and observation of nature?
When Nicholas Copernicus proposed his theory of the skies, it was the most radical scientific proposition that had been made in centuries. Today, the model of the universe around which the planets revolve around the sun is an unquestioned fact. Medieval theories of the cosmos, however, preached an earth-centric cosmos. This was in a similar vein to Aristotle’s propositions about the earth being the centre of the universe around which all else revolved. The Medieval Catholic Church’s assertions were in fact given support through Aristotle’s philosophy, which suddenly found renewed credibility and popularity after the conquest of Spain, which resulted in a revival of Classical Greek philosophers.
Aristotle had claimed that the earth sat at the centre of the universe, stationary, with eight crystal spheres moving around it. These spheres contained the stars, the sun, and the moon and the planets embedded in them. The church, in adopting this theory, added two more spheres, and the notion of a paradise and heaven beyond the spheres. The idea that the earth was the lowest sphere, and the spheres fanned out in a hierarchy until the heavens is a derivation of Aristotle’s thought too. Aristotle’s theory came to be heavily criticised for its relative motionlessness. By placing the sun in the centre, and the earth as only one of several planets moving around the sun, Copernicus not only gave the cosmic model more movement, but also seemed to make it much, much larger than the finite and compact cosmos that Aristotle had described.This also destabilized long established ideas that the Church had normalised for centuries- the idea that the earth was special, and that there was some heavenly concept of perfection that could be attained.