Eudaimonia lecture series: Philosophy and Science in History (Professor Adrian Blau, King's College London)
Historians of philosophy ask two main kinds of questions: (1) empirical questions (e.g. what Hobbes meant by "reason", and why Hume wrote what he wrote), and (2) philosophical questions (e.g. how Hobbes's ideas fit together, and how convincing Hume's arguments are).
(1) The best set of tools that humans have yet developed for answering empirical questions are scientific tools. Part of my paper will thus explain why scientific ideas are far more relevant in history of philosophy than most people think - especially uncertainty, under-determination, falsification (though not in orthodox ways), hypothesis-testing, triangulation of textual, contextual and philosophical evidence, and publicity. The emphasis on testing is crucial.
(2) The second set of questions are philosophical, and philosophical analysis is vital even in primarily historical analyses, since even historians will sometimes need to take a stand on questions such as how an author's ideas fit together and how convincing their arguments are; and issues of conceptual consistency are ever-present, even if only in the background. All of the following philosophical techniques, except the last, are thus required techniques even for historians: conceptual analysis, conceptual/logical implications, presumptions, specifying the steps in an argument, systematic reconstruction, adaptive reconstruction, and drawing contemporary insights. Many historians indeed attempt the last of these techniques, albeit not always effectively.
Overall, I thus argue that while many historians of philosophy hate the idea of doing anything scientific, and while many intellectual historians hate the idea of doing anything scientific or anything philosophical, all of us need to use both of these approaches, and we should thus learn to use their tools better.