 In Whitehead’s London writings, he aims at logically reconstructing Einstein’s STR and GTR, which are both deterministic theories of physics, and his notion of causality (that each occasion presupposes the antecedent world as active in its own nature) does not seem to leave much room for any creative self-determination. In his Harvard writings, however, Whitehead considers deterministic interaction as an abstract limit in some circumstances of the creative interaction that governs the becoming of actual entities in all circumstances, and he makes clear that his notion of causality includes both determination by the antecedent world (efficient causation of past actual occasions) and self-determination (final causation by the actual occasion in the process of becoming). Whitehead writes: