John Philoponus, also known as John the Grammarian or John of Alexandria, was a Greek-speaking philologist, Aristotelian commentator and Christian theologian from Alexandria, Byzantine Egypt, who authored a number of philosophical treatises and theological works. John Philoponus broke from the Aristotelian–Neoplatonic tradition, questioning methodology and eventually leading to empiricism in the natural sciences. He was one of the first to propose a "theory of impetus" similar to the modern concept of inertia over Aristotelian dynamics. He is also the historical founder of what is now called the Kalam cosmological argument. 490 – 570; died at about 80. Alive at the same time as Justinian I, Gregory I, Aryabhata, Boethius, and Benedict of Nursia. Wiki link