ABSTRACTThis article argues that the responses of political parties to social change are mediated by ideology, which offers only a limited range of options. What these are, how and why they are limited, and in what ways they may account for recent political developments are the main themes of the article. They are treated in the context of a general review of the relations between ideologies, parties and change, using a modified model of the traditional Left–Right spectrum based on the concept of a ‘relative and dynamic Centre’. The resulting mode of analysis, here called ‘idealectics’, is illustrated with reference to Western and especially British experience over the last tw