In contrast to metaphysics and rationalism, the Scottish philosopher David Hume (1711-1776) tried to make the experimental method successfully applied in the natural sciences fruitful for the study of human nature. However, his scrupulous orientation towards observation and experience leads him, contrary to expectations, into scepticism, a form of philosophy that can be thought but not lived. According to Hume, therefore, it is not reason but nature that should be the ultimate yardstick for our thinking, feeling and acting. Based on this conception, the introduction discusses Hume's innovative contributions to the theory of knowledge, moral philosophy, aesthetics and philosophy of religion, which may still claim systematic interest today.