 Galileo was one of the first modern thinkers to clearly state that the laws of nature are mathematical . In The Assayer he wrote " Philosophy is written in this grand book , the universe ... It is written in the language of mathematics , and its characters are triangles , circles , and other geometric figures ; .... " His mathematical analyses are a further development of a tradition employed by late scholastic natural philosophers , which Galileo learned when he studied philosophy . His work marked another step towards the eventual separation of science from both philosophy and religion ; a major development in human thought . He was often willing to change his views in accordance with observation . In order to perform his experiments , Galileo had to set up standards of length and time , so that measurements made on different days and in different laboratories could be compared in a reproducible fashion . This provided a reliable foundation on which to confirm mathematical laws using inductive reasoning . 
