Ian Hacking, the distinguished Canadian philosopher of science, visited Taiwan in November 2007 and stayed for 19 days, at the invitation of Professor Yuann Jeu-Jenq at National Taiwan University. During his visit, Professor Hacking delivered a series of four lectures: "On the Historical Roots of Scientific Reason", "Where do Mathematical Objects come from?", "The Laboratory Style of Thinking and Doing", and "Realism and Anti-realism". The first two were keynote speeches given at the Fourth International Conference on Experiences and Truth, which was held at Department of Philosophy in NTU. The third lecture was delivered at the Hacking Workshop organized by STM, and the last one was addressed to Department of Philosophy at Soochow University.