TIME IN A CAUSAL THEORY

We present a causal theory based on an interventionist conception of c ausality, i.e., a preference to select causes among a set of actions w hich an agent has the ability to perform or not (free will). Emphasis is put on the temporal and explanatory aspects of causal reasoning. We introduce a formal framework enabling to define the notion of volunta ry cause in a way allowing for an effective retrieval of causes in a g iven situation. The causal knowledge is represented by causal rules of two kinds: strict and ''normal''. The latter is based on the notions of preferred time lines (futures that the agent normally has in mind w hen (s)he opts for performing the action) and of inhibiting events (th e occurrence of which prevents the anticipated effect to happen). A si tuation is described by a set of events occurring on time lines; this description is completed by default assumptions (when an agent perform s an action, we assume, unless this is inconsistent, that its precondi tions are fulfilled and that no inhibiting event will take place). An example is presented, extension to first-order is briefly discussed, a nd our approach is compared to related works.