Epistemological features of action have been somewhat neglected in the foregoing studies. In Essay 11, lapses of an agent's knowledge about his current behaviour were discussed briefly. Essay III had some remarks on how an agent's non-observational awareness of what he is doing, and why, contrasts with his ordinary perceptual and inductive knowledge of things that caused him to act. One possible exception was allowed : non-observational knowledge that his desires and beliefs were among the causes of his behaviour. Essays IV and V dealt at some length with the logical connections between a man's beliefs, which vary in their unshakeableness, and his attempts and intentions. In the present study I want to explore the relations between one's self-knowledge, of all these varieties, and one's decisions.