  Still, despite rejecting Gilbert and Troitzsch’s characterization of the difference between simulation and experiment, Guala and Morgan both reject the identity thesis. Drawing on the work of Simon (1969), Guala argues that simulations differ fundamentally from experiments in that the object of manipulation in an experiment bears a material similarity to the target of interest, but in a simulation, the similarity between object and target is merely formal. Interestingly, while Morgan accepts this argument against the identity thesis, she seems to hold to a version of the epistemological dependency thesis. She argues, in other words, that the difference between experiments and simulations identified by Guala implies that simulations are epistemologically inferior to real experiments – that they have intrinsically less power to warrant belief in hypotheses about the real world because they are not experiments.