Nancy Cartwright's Philosophy Of Science Research

This dissertation aims to comprehensively analyze the thoughts of Nancy Cartwright, who is one of the most important and influential philosopher of science today. According to the clue of re-construction of scientific knowledge, it analyzes Cartwright's philosophy of science and discusses her main viewpoints of law, explanation, capacity and dappled world.1, According to conventional views, the basic knowledge of science is about fundamental laws, because they can not only represent but explain. But Cartwright argued that there was a tension between laws' truth and explanatory power. True laws can not explain and laws that can explain usually are false. Cartwright provided three different but interrelated arguments for this conclusion. (1) Like phenomenological laws, fundamental laws are also ceteris paribus laws. Because of scarce of laws, we have to explain phenomena by false laws. (2) We usually explain complex phenomena by composition of causes which destroy laws' ceteris paribus clauses. So there is a trade-off between truth and explanatory power. (3) We need approximations that improve on what the fundamental laws dictate when we explain reality. So the manifest explanatory power of fundamental laws does not argue for their truth. In fact the way they are used in explanation argues for their falsehood if we insist Inference to The Best Explanation (IBE). Cartwright thought the appearance of truth comes from covering law explanation, a bad model of explanation. So she proposed an alternative to the conventional picture, a simulacrum account of explanation. According to her, the fundamental laws do not govern the reality but models which is just the simulacrum of reality. In other words, the fundamental laws are true only in models or some concrete systems which are similar to the models.2, Since the fundamental laws are true at best in a few scattered and artificially produced settings, how does science deal with the messy real world. Cartwright argued that scientists achieve these ends not by discovering laws but by discovering stable capacities that recombine in myriad ways to produce the world in which we live in. The fundamental laws should not be understood in regularists' sense, but as ascriptions of capacities. Theses capacities are causal power. Since Hume replaced causal facts with facts about generalizations, empiricists insist that singular causal facts are true in virtue of generic causal facts; and generic causal facts are reducible to regularities. But Cartwright argued that generic causal facts could not be reducible to regularities and the singular facts are primary. Generic causal claims of science are not reports of regularities but rather ascriptions of capacities, capacities to make things happen, case by case. Cartwright drew her conclusion from methods that are applied to the messy real world: linear causal modeling and path analysis as employed in econometrics, medical research, and the life sciences.3, So the fundamental principles of theories in physics do not represent what happens, rather the theory gives purely abstract relations between abstract concepts. For the most part, it tells us the capacities of systems that fall under these concepts. Though knowledge about capacities is more basic than that of laws, virtue is not all on the side of capacities. To affect the world around us we need to make reliable predictions about it and that require regularities. So where do laws come from? According to Cartwright, laws are produced by nomological machines. In any case, it takes a nomological machine to get a law of nature. We apply knowledge about capacities to construct a nomological machine then get a law which is true only in machine. As the mediator between theory and reality, models are the blueprint of nomological machines. Thus Cartwright completed the re-construction of knowledge of science. This re-construction is opposed to the fundamentalism. But for her, it did not mean anti-relaism. Instead Cartwright proposed a new version of realism, local realism. It is wholism of patchwork of laws that make anti-fundamentalism and realism hand in hand. From that, we can see the metaphysical picture of world: a dappled world.4, After discussions of Cartwright's thoughts, we concluded that there was a tension between capacities' stability and open-endedness; it was problematic to infer from scientific practice to metaphysics picture; the method of case study which Cartwright applied was philosophically undetermined.