Among the approaches about the nature of scientific theory, we could refer to positivism and model-theory approaches. These approaches are fraught with difficulties so they couldn’t resolve the problem of scientific theories. The model-theory approach which is the Van Fraassen’s concern, is not acceptable, and . In contrast to these views, Churchland --as a scientific realist-- suggests a sense of realism to resolve the scientific theories’ problem. He uses the achievements of cognitive science and proposes a connectionist model as an alternative to propositional and model-theory approaches, but his suggestion is faced with serious problem: Only by the connectionist models of scientific theory we couldn’t give any representation between these models and the world whereas Churchland takes it for granted, and doesn’t give any reasoning. Here we are going to explain the Churchland’s approach and its backgrounds then we will try to treat its difficulties and introduce cognitive approach as an extension of realism.