Political interaction among citizens who hold opposing moral views commonly requires reaching beyond toleration, toward actual co-operation with policies one opposes. On the more personal level, however, regarding (e.g.) interactions between healthcare providers and patients, several authors emphasise the importance of preserving integrity. But those who oppose any ‘complicity in evil’ often wrongly conflate instances in which the other's position is (and should be) totally rejected with instances of legitimate, although deep, disagreement. Starting with a striking example from the context of a particular tradition, I argue generally that in the latter sort of disagreements, talk of ‘complicity’ should be largely replaced with a more co-operative moral stance, grounded in a pluralistic framework. Co-operation Despite Disagreement (CDD) should be sought either for institutional reasons – akin to the political – or for relational reasons. CDD involves sharing another's perspective and sometimes calls for adopting another's moral judgements in preference to one's own. I seek to identify some of the conditions and circumstances that would justify such a shift, particularly in scenarios involving assistance, such as physician-assisted suicide (PAS) or the role of an anaesthesiologist in abortion. This discussion is meant to provide examples of the kind of second-order reasons appropriate for determining the terms for CDD – in distinction from first-order considerations (e.g., the much-contested ‘active/passive’ distinction) which are likely to be the subject of the initial disagreement and hence cannot serve to resolve it. [ABSTRACT FROM AUTHOR]