"The distinctive thesis of Rand’s on political economy is her insistence that the best defense of liberalism is philosophical—i.e., that it turns on getting the metaphysics, the epistemology, and especially the ethics right. Wrong views in ethics and epistemology undercut the case for a free society. And on those issues, her views frequently conflict with those of Smith (especially in moral psychology) and they consistently conflict with those of Hume (especially in epistemology)."