When we attempt to apply the principles of ethical expertise - which originated, after all, in the field of biomedicine - to the sphere of culture, we face the fundamental problem of any expertise: the lack of a methodology that will enable at least the partial elimination of the influence of “subjective factors”, ranging from experts' ideological and religious preferences to their personal moral qualities and emotional responses. This paper aims to develop such a methodology. To resolve this problem, the author proposes to revisit the forgotten art of casuistry, which was flourishing at the end of the 16th and beginning of the 17th centuries. At that time, the golden rule of casuistry was to regard various ethical principles and norms as more or less plausible opinions ( opinion probabilis ). One could choose one of these opinions only after discussion and evaluation of each opinion and its outcomes in each specific case. Today, the use of casuistry in ethical expertise means that experts can proceed not from their own convictions and principles, but from an assessment of a specific situation, and a comparison between possible consequences resulting from the application of certain moral requirements to that situation. Only those conclusions which satisfy all the experts can be termed “justified”. However, such a consensus will be impossible if the experts base their conclusions not on an analysis of the consequences of a specific decision, but on their own favoured religious or ideological doctrines. Theoretically speaking, the author believes that casuistry as a method of ethical expertise implies not only an assessment of a particular case from the point of view of the general principles of morality but also the evaluation of these principles in light of their applicability to particular cases.