Contemporary American medical ethics was born during a period of social ferment, a key theme of which was the espousal of individual rights. Driven by complex cultural forces united in the effort to protect individuality and self-determined choices, an extrapolation from case law to rights of patients was accomplished under the philosophical auspices of ‘autonomy’. Autonomy has a complex history; arising in the modern period as the idea of self-governance, it received its most ambitious philosophical elaboration in Kant's moral philosophy. (...) In examining the Kantian construction, it is evident that neither his universal moral imperative nor his rigorous application of self-legislated ethical action can sustain our own notions of moral agency in a pragmatic, pluralistic society. But the Kantian position is useful in highlighting that self-governance is not equivalent to ‘autonomy’, and this distinction defines the limits of autonomy in the clinical setting. A critique of Engelhardt's idea of ‘principle of permission’ is used to illustrate autonomy's eclipse as a governing principle for medical ethics. (shrink)