This paper develops an account of consciousness in action. Both consciousness and action are related to knowledge. A voluntary action is defined as a volition, or something intentionally effected by means of such volitions. Volitions are conscious mental acts whose proper function is to make their content true. A mental act is the exercise of a power of mind and a conscious mental act is identical with knowledge of its own phenomenal character. This set of definitions elucidates the relations between consciousness, action and knowledge.