ABSTRACT
The rule of inference to the best explanation (IBE) has been widely used in the philosophy of science especially to defend scientific realism’s claim that hypotheses referring to unobservables such as unconscious wishes or black holes can be empirically confirmed. There was a time when many hermeneutically oriented supporters of psychoanalysis endorsed a causal replacement thesis. After a sustained debate among psychotherapists about what counts as evidence, the American Psychological Association appointed a presidential task force to examine the issues. Many scientists and philosophers hold that if one theory has more explanatory power than a rival, or is simpler or more parsimonious in that it postulates fewer types of entities, then it should be preferred. A more defensible view is that when and only when two competing theories are empirically equivalent, simplicity, explanatory power or parsimony can break the tie.
