Hume’s Actual Theory of Motivation
So far, I have tried to situate Hume’s philosophy of action within his wider empiricism. Actions, approached in this way, are external objects in the sense of being things that we can observe through the senses. Accordingly, our knowledge of them is not a priori but empirical, mediated through perceptual impressions. Mutatis mutandis, Hume maintains that proposed explanations of action – whether singular or general in scope – are to be tested through experience, either directly or through testimony (T Intro.10/xviii; quoted in Chapter 1.1). None of this entails that the reasons for which we act are themselves external, observable, objects. Rather, their existence is to be inferred from our behaviour.