Karl Marx and Sigmund Freud provided powerful accounts of systematic interested ignorance. Fifty years ago, Anglo-American philosophies of science stigmatized Marx's and Freud's analyses as models of irrationality. They remain disvalued today, at a time when virtually all other humanities and social science disciplines have returned to extract valuable insights from them. Here the argument is that there are reasons distinctive to philosophy why such theories were especially disvalued then and why they remain so today. However, there are even better reasons today for philosophy to break from this history and find more fruitful ways to engage with systematic interested ignorance.