This thesis examines the roles played by history in Charles Peirce’s philosophy of science. History is seen to have two roles. First, it contributes to the philosophy of science: in examining the history of science we are able to learn about science and scientific progress. In this way, studying history can teach us about inquiry itself. Secondly, history is the subject of the philosophy of science. The methods of inquiry learned about and developed in the philosophy of science should be applied to historical inquiries. In this way, history contributes to philosophy of science, and historians (among other scientists) benefit from this contribution.