Muddles can be instructive. The clarifying confusion to be examined in this paper is Isaiah Berlin's intelligent vacillation on the issue of whether or not the extent of a person's freedom depends on his desires. Is the amount of freedom an agent possesses determined solely by his objective circumstances or is it also partly a function of his subjective tastes and preferences? In clarifying this question I shall suggest that Berlin has trouble answering it because he almost perceives that interpersonal (...) cardinal measurement of freedom, if possible at all, is possible only on a subjective basis. Yet as Berlin eloquently reminds us measuring freedom according to a subjective metric generates paradox. Whether commonsense ideas of freedom are consistent and reasonable is not purely an academic issue, for we do often make political judgments to the effect that one or another policy, or a movement to one or another form of society, can be expected to reduce or enlarge human freedom. If freedom is not measurable these judgments are merely hortatory. (shrink)