I use biography, I use literary connections (as with Platen - this seems to me extremely helpful for appreciating the nuances of Mann's and Aschenbach's sexuality), I use philosophical sources (but not in the way many Mann critics do, where the philosophical theses and concepts seem to be counters to be pushed around rather than ideas to be probed), and I use juxtapositions with other literary works (including Mann's other fiction) and with works of music. - Philip Kitcher