Precedent autonomy and personal identity

Debates on precedent autonomy and some forms of paternalistic interventions , which are related to questions of personal identity, are analyzed. The di scussion is based on the distinction between personal identity as persisten ce and as biographical identity. It first is shown that categorical objecti ons to advance directives and "Ulysses contracts" are based on false assump tions about personal identity that conflate persistence and biographical id entity. Therefore, advance directives and "Ulysses contracts" are ethically acceptable tools for prolonging one's autonomy. The notions of personality and biographical identity are used to analyze the ethically relevant featu res. Thereby, it is shown that these concepts are operative in and useful f or thinking in biomedical ethics. The overall conclusion is that categorica l arguments against precedent autonomy or "Ulysses contracts" are based on misleading theories of personal identity and that advance directives are an ethically respectable tool for prolonging individuals' autonomy in cases o f dementia and mental illness.