abstract:John Philoponus (; }}; 490 – 570) also known as John the Grammarian or John of Alexandria, was a Christian and Aristotelian commentator and the author of a considerable number of philosophical treatises and theological works. A rigorous, sometimes polemical writer and an original thinker who was controversial in his own time, John Philoponus broke from the Aristotelian-Neoplatonic tradition, questioning methodology and eventually leading to empiricism in the natural sciences.