In this life, there are three kinds of men, just as there are three sorts of people who come to the Olympic Games. The lowest class is made up of those who come to buy and sell, the next above them are those who compete. Best of all, however, are those who come simply to look on. The greatest purification of all is, therefore, disinterested science, and it is the man who devotes himself to that, the true philosopher, who has most effectually released himself from 'the wheel of birth'.
John Burnet, Early Greek Philosophy, as quoted in discussion of the philosophy of Pythagoras in Bertrand Russell's A History of Western Philosophy