John Stuart Mill (1806–1873) is to this day studied most for his work on ethics, which codified utilitarianism, one of the three major philosophical moral systems, along with virtue ethics and deontology. However, he had important political influence, too, as a British progressive, and also codified the empirical philosophy of science. His contributions to both democratic progress and the philosophy of science were so influential that they are often taken for granted politically and in definitions of science, without a perceived need to trace their authorship.