MCMP – Mathematical Philosophy (Archive 2011/12) is a large archive of recorded academic talks, each opening with a one-line credit to LMU Munich. The premise is in the name. Philosophical questions are taken up with the tools of logic and mathematics, and the speakers argue through definitions, derivations and formal semantics. Carnap is the clearest recurring figure. One talk follows his approach to theoretical terms from his 1939 monograph Foundations of Logic and Mathematics, through the Ramsey sentence and Hilbert's epsilon operator, to Philosophical Foundations of Physics in 1966, a work based on a typescript of his 1958 UCLA seminar made by Martin Gardner. Its speaker opens by promising no Quine, a line aimed at the anti-Harvard people in the room. A second talk, 'Carnap on extremal axioms and categoricity', comes from a fellow of the center who came from Vienna and who points out the talk's close ties to a colleague's. Modality is the other strong thread. In 'Modality and Categories', a speaker whose main research area is category theory builds a category out of sets and functions in a few sentences, then observes that its unit and composition laws do the work that reflexivity and transitivity do for an ordering. The talk closes by suggesting modal logicians could both learn from and add to the study of adjunctions and monads. 'Possibilities without possible worlds/histories' approaches modality from another side. Possible worlds revolutionized philosophy from the 70s on, its speaker grants, but they are too crude a tool, and branching continuations are proposed as something subtler and more local that can still give a semantics for tense and modality. The range runs wider still. An introduction to adaptive logics is given by someone candid about not having invented them but who feels a duty to spread the word, and it ends on finitistic non-triviality proofs, full comprehension without losing too much classical mathematics, and an apology for running out of time. 'Three contrasts between two senses of coherence' opens with a Carnegie Mellon speaker recalling a long collaboration with two statistics colleagues that began in 1979, when a course dwindled to three people, and joking that each department counts the speaker as a member of the other. Expect density. Passages turn on terms like lower limit logic, marked lines and final derivability, and one speaker's promised pictures of Carnap cannot be seen on audio. The recordings keep the room as well: introductions, thanks, references to talks given earlier at the same gatherings. 'Modality and Categories' makes a good first listen, since its speaker stops to define the central idea before building on it. The two Carnap talks then make a natural pair.