When are two explanations better than one? This question lies at the heart of the CESAR project. There are many contexts where multiple explanations might be under consideration – scientific investigation, medical diagnosis, historical research, detective work, to mention a few. Sometimes the goal is to compare the explanations on offer in order to identify the best one, that is, the one that best explains the evidence. However, in other cases this approach might be too restrictive; it could be that embracing two (or more) explanations provides a better account of the relevant evidence. But how do we decide when two (or more) explanatory hypotheses can work together as a ‘conjunctive explanation’ rather than as distinct, competing explanations? The CESAR project investigates conjunctive explanation from a) a formal perspective that involves probability theory and computer simulations, and b) a history of science perspective.

How are conjunctive explanations relevant to science and religion? The CESAR project explores two possibilities. First, religious beliefs might shape attitudes towards the relationship between multiple explanations within science. In particular, religious beliefs might have a bearing on whether different scientific explanations are viewed as competing or potentially working together as a conjunctive explanation. Second, particular scientific and religious explanations might be taken to work together to provide a more adequate conjunctive explanation rather than being considered as rivals. While there is general agreement that science and religion need not be in conflict, the CESAR project investigates the much more positive thesis that scientific and religious explanations can work together in mutually enriching ways. These issues will be explored in the context of both the history of science and religion and in current debates.

The CESAR project is a collaboration between Ulster University, the University of Utah, and Queen’s University Belfast and is funded by the John Templeton Foundation. It builds on an earlier project on ‘Explaining and Explaining Away’ at Ulster University, which was also funded by the John Templeton Foundation.

The Executive Summary for the project can be found here.