Do you think every true cause of an event is the event's catalyst? Do you think that some "activation potential" must be crossed for any event which may occur to occur? Do you think that some "activation potential" must be crossed for a meme to propogate further? If a given cause is never a catalyst, is the cause never determinate? If the cause is never determinate, may it ever be intelligible? If it can never be intelligible, can science study it?