For ancient philosophers, philosophy was not only a theory about the big questions but also a way of life, yet it was not only a way of life but also a theory. Pierre Hadot showed the importance of philosophy as a way of life in antiquity. Moreover, he defended, as this paper demonstrates, the view that ancient philosophy was primarily a way of life and that philosophical discourse or theory played a secondary role. The paper argues against Hadot, taking the (...) paradigmatic Socratic way of life as an illustration, that theory is as crucial for philosophy as practice is. Doing spiritual exercises and living in a particular way was very important for the ancients, but so were truth and understanding reality. (shrink)