As a clinician, sometimes I must justify to patients and myself how far my professional role may extend as their doctor, particularly in cases of misunderstanding or disagreement over a clinical issue. For example, in attempting to advise a parent who is strongly against childhood vaccination, I have found that it might be misconstrued as disrespectful, and it is ineffective to simply cite “best available evidence”, if we cannot agree on how to determine what are the potential possible harms and benefits of vaccination. The parent may argue that they have other values that take precedence over my comparatively narrow conception of health. However, plausibly there is room for debate if I may engage in dialogue over beliefs and values if not “evidence”. This paper argues that common conceptions of the doctor - patient relationship not only have a philosophical basis more fitting some forms of contractualism than other ethical theories, but that by using contractualism, doctors and patients can decide together, what health beliefs and values that pertain to health, either party can reasonably tolerate or support. While I briefly detail several philosophical accounts of contractualism, I defend an account of contractualism that has a strong focus on what individual doctors and patients owe each other. I argue that Scanlon’s ethical theory fits well with several models of the ideal doctor patient relationship, particularly Emmanuel and Emmanuel’s widely cited “ideal deliberative model”.