We have noticed at least two philosophically significant features that set human actions apart from every other type of event. One singularity appeared in Essays V, VI and VII, but has not been emphasized: the 'social fact' that your actions are events for which you may have to bear responsibility. The other earmark of action that interests me now was discussed at length in Essay 11. This is the 'linguistic fact' that we characterize people's behaviour by reference to their concurrent mental states - for example, when we report that someone deliberately, or perhaps unintentionally, started a fire. Both these traits of action take on dear relief, and become mutually relevant, in criminal law and some areas of civil law, notably tort. An agent's mental state is one factor we consider in determining how responsible he iso Most criminaI and some civilliability requires that he should be aware of what he is doing and intend to be doing it. If he was in one of the recognized excusing conditions of mind, such as ignorance or insanity, then this requirement of awareness and intention is unsatisfied. Now is there such a requirement for every type of criminal offence, or can we delineate a dass of illegal actions in which the lawbreaker may be punished even though he lacked both control and awareness? Plainly it would be a conceptual advance if I can make good either answer.