Aristotle theorises that there are two parts of the soul that engage in thought: the part that deals with contingent, everyday, affairs, and the part which deals with theoretical, scientific, matters. He posits two different kinds of reasoning, each one suited to a different part: deliberative reasoning for the part dealing with contingent matters, and syllogistic reasoning for the part dealing with theoretical matters. The types of reasoning involved are very different: one is essentially means-end reasoning, and the other is deductively valid logical reasoning. However, there are several structural similarities between the two types of reasoning: both are types of reasoning concerned with discerning causes, since in both domains, knowledge of a proposition consists in grasping its explanation, and both types of reasoning require something called noûs, a cognitively demanding sort of knowledge whose domain is propositions which are the starting-points of those explanations. In this talk, I explore the similarities and differences between theoretical and practical noûs, and argue that each is a necessary constituent of achieving the highest possible form of knowledge in the relevant domain.
Benjamin Morison studied in Oxford with Jonathan Barnes and Michael Frede, was assistant at the University of Geneva before returning to Oxford in 1997 as a British Academy Postdoctoral Fellow, and subsequently Michael Cohen Fellow in Philosophy at Exeter College (2001-9). Since 2009, he has been Professor of Philosophy at Princeton University, and has directed the Interdisciplinary Program in Classical Philosophy since 2014. He has held visiting positions at Princeton University, Humboldt Universität zu Berlin, Renmin University in Beijing, and the Sorbonne Paris-IV. Publications include "On Location: Aristotle’s Concept of Place" (OUP, 2002), contributions to the Cambridge Companion to Galen, the Stanford Encyclopedia entry on Sextus Empiricus, and numerous papers on Aristotle. He is co-editing with Hendrik Lorenz the Symposium Aristotelicum volume on "Eudemian Ethics book II". He works primarily on logic, epistemology, physics, and geometry in the ancient world.