  The early extant work of “John the Grammarian,” on ambiguous words in Greek distinguishable only by their accent, is philosophically insignificant. So I leave these aside, and pass on to give an overview in this section of his extant philosophical writings, first and foremost his commentaries on Aristotle. In order to appreciate the magnitude of Philoponus’ achievement as philosopher and scientist, one has to take into account, at least partially, the intellectual culture in which he was brought up. A common way that philosophers in late antiquity developed and propagated their own ideas was by composing commentaries on the classical philosophical texts of Plato and Aristotle.  Generations of such commentaries were written from the time when Aristotle’s works became again accessible to a wider audience in the first century BCE down to the seventh century CE and beyond, forming a rich and largely coherent tradition. The majority of ancient commentaries still extant today were written by Neoplatonists as textbooks for their philosophical courses. Typically, these works have a number of features in common: