Critical realists argue that the condition of possibility of the sciences is that they are based on a correct set of ontological assumptions or definitions. The task of philosophy is to underlabor for the sciences, by ensuring that the explanations developed are congruent with the ontological condition of possibility of the sciences. This requires critical realists to justify their claims about ontology and, to do this, they turn to ontological assumptions that are held to obtain in natural scientific knowledge and (...) social agents’ lay knowledge. A number of problems with this approach are discussed and a problem-solving alternative is advocated. (shrink)