The views of Isaiah Berlin are an influential example, in the philosophical literature, of what we might call perfectionist liberalism, a type of liberal political view that spells out a set of controversial metaphysical and ethical doctrines concerning the nature of value and the good life, and then goes on to recommend political principles built upon these values. Berlin's formulations, though influential, are characteristically compressed and allusive, but Joseph Raz has developed a closely related set of ideas with great explicitness and clarity. For Raz, the key personal and political value is autonomy, a power of self-direction and selfgovernment. To this (and here is the connection to Berlin) he links the acceptance of moral pluralism: to see why only a relatively extensive range of options adequately supports autonomy, one must grasp the fact that there are many incompatible ways of living, all of which are morally good and valuable. Thus Raz's doctrine of autonomy-as he statesrequires the acceptance of moral pluralism and uses that idea to support its account of adequate options. Religious and secular toleration, he argues, should be based on an acceptance of the ideal of autonomy and This article was first written for a conference on Isaiah Berlin at