Scholarship on Aristotle’s theory of visual perception has traditionally held that Aristotle had a single, static, conception of light and that he believed that illumination occurred prior to and independent of the actions of colours. I contend that this view precludes the medium from becoming actually transparent, thus making vision impossible. I here offer an alternative to the traditional interpretation, using contemporary conceptual tools to make good philosophical sense of Aristotle’s position. I call my view the ‘ecological’ interpretation. It postulates (...) two conceptions of light: non-visible mobile propagated light and visible static illumination produced by the interaction of propagated light with the environment’s coloured textured surfaces. I argue that these contemporary conceptual tools can find a foothold in and consistently enrich Aristotle’s extant position and that, with their aid, we can restore coherence to his theories of light and vision. (shrink)

The present text is the revised and corrected English translation of the book published in German by the Lang Verlag, Bern 2008. Unfortunately the text still has some minor flaws (especially in the Index Locorum) but they do not concern the main thesis or the arguments. It will still be the final version, especially considering my age. It is among the most widespread and the least questioned convictions that in Metaphysics Lambda Aristotle presents a theology which has its basis in (...) a metaphysics of substance. Doubts about theological interpretation are beginning to stir in a growing number of publications, but nevertheless the majority of research literature, compendiums and histories of philosophy argues within this frame. A closer look at the facts reveals that this conviction has no basis in the text. Quite the contrary it is based on a reception with theological interests. It arised over centuries, starting from Patristic times and the Middle Ages; it was influenced by Neoplatonic texts as the Liber de Causis or the Theologia Aristotelis, texts for a long time considered as original Aristotelian books. And, if you read not translations but the Greek text, you see that the word 'god' occurs much less than in a theological book should be. In some translations we find more occurences of that word, and especially in French, Italian, English translations some words as le Bien, l'Intelligence etc. are written with capitals to inticate that it is about god. To make it even more clear, we read often the term 'First Mover' or 'Unmoved Mover' as an other name for god, but this expression is never used by Aristotle. So the reader has the impression that Aristotle speaks continuously about god. In addition, in the present book you will find arguments which clean up with the outdated concept of substance in the Aristotelian text, a concept which was developed for quite other problems than Aristotle had, namely theolgical ones. And, if there is no substance, there is no corresponding metaphysics of substance and no theology or onto-theology. If substance, metyphysics, theology play no role in Metaphysics Lambda, what else is its content and aim? That is not so difficult to say because Aristotle says it sufficiently clear in his first sentence, περὶ οὐσίας ἡ θεωρία: our inquiry is about being; its aim is to develop the Frage nach dem Sein and to state a speculative answer: being is noesis, Sein ist Gewahren. (shrink)

The theological teachings of John Philoponus are important for several reasons: a) to see the real achievements and influences of Aristotelian logic in regard to theology, b) to see the real consequences of not accepting hypostasis as relational and ontologically based and c) to assess the real consequences of such teachings for Triadology and Christology.

Sixteenth century pharmacology was still very much under the influence of a distinction going back to ancient medicine: the distinction between effects of medicaments that were taken to be explainable by the elementary qualities, their mutual modification in mixture, and the combination of these modified elementary qualities on the one hand, and the effects of medicaments that were taken not to be explicable in this manner.1 Galen coined the expression that a medicament of the latter kind possesses the capacity of (...) acting "by its whole substance,"2 and the question of how actions of the whole substance could be explicated gave rise to heated controversies in early modern pharmacology. Did Galen just... (shrink)