Even where this is not the case the most seductive rewards and the severest punishments will never succeed in preventing some of the members of a system from pursuing what they consider to be their inextinguishable interests and from seeking with varying degrees of success to change the goals and norms of the system this is one of the important sourees of political change closely associated with changes in the inputs of demands that are due to a changing environment but we cannot pursue this crucial matter of the nature of political change as it would lead us oft in a new direction