Abstract

According to majority of contemporary ethicists, the so-called problem of the „dualism of the practical reason”, as formulated by Henry Sidgwick in his book Methods of Ethics calling it the „deepest problem of ethics”, still lacks an adequate theoretical solution. The problem, in short, is the assumption that our practical reason strives for two equally rational and justifiable goals – our own good and the common good – and that it is not always possible to count on a successful resolution of a possible conflict between self-interest and concern for common good. This would, in the final analysis, lead to the suspension of rational decision- making. However, Peter Singer and Katarzyna de Lazari-Radek, authors of a notable monograph on Sidgvick, believe that the problem of the dualism of the practical reason can be solved if we resort to one kind of evolutionary explanation of moral beliefs.