The last time he taught it, the final time he taught it, he never got beyond the first sentence, ? "I went down to the Piraeus." What does it mean?

但上次上课时，也是他最后一次讲这门课时，他根本没离开过第一句，“我南降皮里亚斯“，这句意思为何？

耶鲁公开课 - 政治哲学导论课程节选