Abstract

The role of intensity in Aristotelian philosophy is obscure. The problem has historically been approached through his logic and categorical sense of motion. Scholars have largely failed to consider the role of intensity in psychology and ethics, the consideration of which greatly clarifies the situation. To this end, I identify three types of intensity present in the corpus Aristotelicum: comparative, modal, inceptive. I show that the intensity of physical contraries is primary in nature but is different from those found in organic processes. I then show that the intensifications found in life, produced by the soul, are of paramount importance to Aristotle’s philosophy. Inceptive intensity is the backbone of psychical activities: concoction, sensation, pleasure, perception, effort, attention, and self-awareness. I outline two essential characteristics of these intensifications: (1) they imply an intransitive causality that is intrinsic to the entity’s nature or form; (2) that they involve an interaction of many parts which mutually amplify each other so that the whole is beyond (irreducible to) the totality of the parts. I end by comparing Aristotle’s views on intensity to contemporary ideas of emergence: feedback, holism, intentionality, and supervenience.