Philosophy 382 Bradford Skow Handout on Locality Definition: D1. C is a direct cause of E =df. C causes E, and there is no event X (different frm C and E) such that C causes X and X causes E. Preliminary definitions of "spatial locality" and "temporal locality": D2. Spatial Locality =df. There is no gap in space between E and any of its direct causes. D3. Temporal Locality =df. There is no gap in time between E and any of its direct causes. A fact about the structure of time and space: Between any two times there is another time. Between any two points of space there is another point of space. An argument that D3 is an incorrect definition: This argument is based on a scenario in which an event has no direct causes. We discussed the scenario in class. 1. If D3 is a correct definition of "temporal locality", then temporal locality is true in the scenario. 2. Temporal locality is not true in the scenario. 3. Therefore, D3 is not a correct definition. Final definitions of "spatial locality" and "temporal locality": D4. Temporal locality =df. For any event E, if C is a cause of E, then for any amount of time t (no matter how small), EITHER (i) C is a direct cause of E and the temporal gap between C and E is less than t, OR there is an event X such that (i) C is a cause of X (ii) X is a cause of E (iii) the temporal gap between X and E is less than t. D5. Spatial locality =df. For any event E, if C is a cause of E, then for any distance d (no matter how small), EITHER (i) C is a direct cause of E and the spatial gap between C and E is d, OR there is an event X such that (i) C is a cause of X (ii) X is a cause of E (iii) the spatial gap between X and E is less than d. The Contingency Principle: If C is a cause of E, the it is possible that C occur but E does not.