Reshaping the Concept of Substance: The Renegade Ockham

Abstract

The aim of medieval epistemology had been to find the adequation between the general substantial form that makes a thing what it is, and the form that is accepted in human reason. The first and decisive general theory of this adequation is to be found in Al-Farabi's treatise on the intellect (Fi l-aql). This theory had been elaborated in a somewhat naturalistic manner by Roger Bacon's theory of the multiplication of species, which as a by-product founded the modern theory of perspective and optics in line with another muslim philosopher, Ibn al-Haitham. In turn, this theory was challenged by several medieval thinkers and finally rejected in its entirety by William of Ockham. For Ockham the question is not whether and how we can grasp the general form that constitutes the essence of a thing, and the forms that convey their attributes, but rather how we can get enough knowledge of a thing by acquaintance in order to be able to think about that thing abstractly in its absence. This move is followed by sceptical attitudes and a different development in the question of the nature of things that finally leads to a basically technical orientation in the general attitude towards nature.