Cognitive science of science attempts to explain a range of phenomena familiar to philosophers of science, such as theory choice and scientific discovery. The appeal to cognitive science may be seen as an attempt to naturalize the philosophy of science. I examine and criticize several of the most important contributions to this new field. I argue that an unrecognized common defect of this work is its reliance on an explanatory approach that takes individuals’ cognitive capacities as its units of analysis. I introduce the term "cognitive individualism" to identify this position, and conclude by examining the position in detail and sketching alternative approaches to naturalizing philosophy stressing the social dimensions of science. In Chapter 1 I briefly describe the field of cognitive science, and outline the empirical resources it can provide a philosopher of science. I then outline key themes of current cognitive science of science. In the next four chapters I critically examine the work of four prominent cognitive scientists of science: Herbert Simon, Paul Thagard, Ronald Giere, and Paul Churchland. All share the same goals of naturalizing philosophy of science by using the empirical resources of cognitive science. I show that all four accounts ignore the important social nature of science, and share an adherence to cognitive individualism. In the final chapter I develop the notion of cognitive individualism in detail. I show that relying on empirical evidence from work in cognitive psychology on human judgment, and work in the sociology of science is more fruitful for explaining science than the current cognitive individualist approach. I conclude with several theses that act as guidelines for future research in naturalized philosophy of science. / Ph. D.