Increasingly, contemporary medical ethicists have become aware of the
need to explicate a foundation for their various models of applied eth
ics. Many of these theories are inspired by the apparent incompatibili
ty of patient autonomy and provider beneficence. The principle of pati
ent autonomy derives its current primacy to a large extent from its le
gal origins. However, this principle seems at odds with the clinical r
eality. In the bioethical literature, the notion of authenticity has b
een proposed as an alternative foundational principle to autonomy. Thi
s article examines this proposal in reference to various existentialis
t philosophers (Heidegger, Sartre, Camus and Marcel). It is concluded
that the principle of autonomy fails to do what it is commonly suppose
d to do: provide a criterion of distinction that can be invoked to set
tle moral controversies between patients and providers. The existentia
list concept of authenticity is more promising in at least one crucial
respect: It acknowledges that the essence of human life disappears fr
om sight if life's temporal character is reduced to a series of presen
t decisions and actions. This also implies that the very quest for a c
riterion that allows physicians to distinguish between sudden, unexpec
ted decisions of their patients to be or not to be respected, without
recourse to the patient's past or future, is erroneous.