ABSTRACT
Not all human motion is behaviour. Each of us in this room is moving eastward at about 700 miles an hour, carried by the diurnal rotation of the earth, but this is not a fact about our behaviour. When I cross my legs, the raised foot bobs gently with the beat of my heart, but I do not move my foot. Behaviour consists in things we do, whether by intention or not, but where there is behaviour, intention is relevant. In the case of actions, the relevance may be expressed this way: an event is an action if and only if it can be described in a way that makes it intentional. For example, a man may stamp on a hat, believing it is the hat of his rival when it is really his own. Then stamping on his own hat is an act of his, and part of his behaviour, though he did not do it intentionally. As observers we often describe the actions of others in ways that would not occur to them. This does not mean that the concept of intention has been left behind, however, for happenings cease to be actions or behaviour only when there is no way of describing them in terms of intention.
