Abstract

The following paper discusses John of St. Thomas’ study of the way in which a habit (moral or epistemic virtue or vice) is a cause of an action it prompts. I begin with contrasting the question of causality of habits with the general question of the causal relevance of dispositions (2). I argue that habits constitute a very peculiar kind of dispositions marked by the connection with the properties of being difficult and being easy, and there are some special reasons to admit the irreducibility of dispositions of this kind. I argue also that there is a special sort of causal connection between a habit and an action it actually prompts. Then I present an analysis of four theses of John of St. Thomas on the causality of habits, which, I think, constitute the most mature and reliable study of the causality of habits in the scholastic tradition: (i) Habits are efficient causes of actions they prompt (3.1). (ii) Virtues do determine the very natures of actions they prompt (3.2); (iii) Virtues do not have a proper counterpart among the characteristics of actions they prompt (3.3); (iv) The formal object of causality of virtue is a masterpiece performance of an action (3.4). In my analyses of John’s arguments for these theses I make three claims: not all powers are “in state of readiness for action”; habits are powers of powers or dispositions of powers; the general concept of a strategy is the key to grasp the properties of being difficult and being easy, and habits should be analysed as a kind of strategies.