The title of this essay is a free-floating reference to conversations I have had with my mathematical colleagues over the last few years about the extent to which the classes we teach within our departments ought to inform and connect with the subjects students are studying in other departments. These discussions often end with a complaint such as, “You can't talk to our engineers, they won't listen.” or “The biologists just don't care about the math their students take.” or “How can you expect an English teacher to have an idea what kinds of math students ought to know?” I'm not sure whether such comments were made with the specific intention of ending an uncomfortable conversation, but they certainly had that effect. I would also be willing to bet that conversations with the engineers, the biologists and the English professors had stopped sometime earlier, if indeed they had ever happened in the first place.

We are at a critical place in the history of mathematics education. Mathematical thinking has insinuated itself into every scientific discipline, including social science. Science and technology in turn have affected every aspect of human society, including art, literature and music. It would be a particularly inappropriate moment for the community of mathematicians to turn inward upon itself for answers to questions concerning the education of students in all disciplines. We must seek these answers jointly with scholars in every area. Only in this way can we construct mathematics courses meaningful to students with a variety of interests and inclinations.