  The greatest challenge for a student of this period of the history of philosophy is to understand how a phenomenon such as Philoponus could have occurred at all. To be sure, elusive individual qualities of his mind and personality must have played an essential rôle, but it is equally true that philosophical, social, and religious parameters are likely to have supplied conditions which allowed him to carry forward his unprecedented and unparalleled challenge to a widely accepted intellectual tradition.  In the past, scholars have readily pointed towards the presumed fact that Philoponus was first raised as a Christian who later came into privileged contact with Greek rationalism; it is supposed that this constellation catalyzed his stance of critical opposition and rejection. However, this explanation is far from satisfactory. Many Christians from birth both before and after Philoponus were similarly exposed to pagan philosophy without reacting in a comparable way.  Other scholars have suggested that Philoponus may have received orders from clerical superiors to write a refutation of Aristotelianism. Again others, especially with a view to the invention of the theory of impetus, have sought the roots of Philoponus’ intellectual emancipation in broad socio-economic changes which occurred in late antiquity, in particular the emancipation of slaves. In whichever way the epithet ‘Philoponus’ is eventually going to be explained, it seems certain that what essentially enabled Philoponus to operate both as a critic of Aristotelianism and as a constructive thinker in his own right was somehow tied up with a new understanding of what one ought to do when one is reading and interpreting the philosophical texts of Plato or Aristotle. Whereas Neoplatonists, especially since Proclus (412–485), tended to approach these ancient texts as a fabric of venerable signs pointing per se and in an infallible way to a higher reality and to the truth, Philoponus read them (as we do today) as indicators of the thoughts and intentions of fallible authors. His more measured hermeneutic approach allowed Philoponus to point out problematic tensions, inconsistencies, and glaring contradictions in the Aristotelian corpus, and to highlight instances of substantive disagreement between Plato and Aristotle. In contrast, the program of the Neoplatonic tradition he grew up in had been, largely, either to ignore such hermeneutical problems or explain them away in an effort to harmonize the rich and diverse tradition of pagan Greek philosophy.