ABSTRACT
In her first book, How the Laws of Physics Lie, Nancy Cartwright provided a wide-ranging critique of a realist attitude to any explanatory scientific theory. Cartwright argued, roughly, that the explanatory power of a theory is at odds with its descriptive accuracy. The greater the “covering power” of a theory the more idealised and further from the truth the theory will be. Cartwright promoted instead the position known as “entity realism” or “experimental realism”, according to which it may be possible to have a justified belief in the existence of some unobservable entity postulated by science, independently of any justification for our current best theory about that entity. Experimental realism thus achieves a combination of common sense realism about some unobservable entities with a principled nonrealism about theories.
