 Voluntary consent is usually thought incompatible with  coercion,  which philosophers define, roughly, as a threat to make someone seriously worse off than she is or should be, unless she consents (Wertheimer 1987). Nonetheless, the prevailing medical ethos tends to treat more cases as cases of coercion than this philosophical definition would suggest. A threat to cause even slight pain unless a patient acquiesces would be taken to invalidate her consent. It would do so even if the patient and the physician have common knowledge that it would not make her seriously worse off and so, that it would not amount to coercion. A threat to deny preventative intervention that is not otherwise owed—which therefore rarely amounts to a threat to make the patient worse off than she is or should be—unless the patient consents to an intervention would also be frowned upon.