The natural sciences have many simple visual models. Mostly they are “wrong", but their structure captures sufficient key operational features to be extremely useful in thinking and communicating. The Nils Bohr (“solar system") atom is one such. The idea that electric power flows through wires and circuits is another. “Network diagrams" of complex molecules is a third. Research I did for US Intelligence after September 11 led to a simple (category-theory like) diagram that shows promise for structuring thought, communication, and action in the field of teaching and learning. It has already proved useful in two military domains: the treatment of PTSD in returning military veterans and the design of robots to perform search-and-rescue and explosive device detection/de-fusion. Bio: Dr. Keith Devlin is an emeritus mathematician at Stanford University, a co-founder and Executive Director Emeritus of the Stanford H-STAR institute, a co-founder of the Stanford mediaX research network, and a Senior Researcher Emeritus at CSLI. He is a Fellow of the American Association for the Advancement of Science and a Fellow of the American Mathematical Society. Much of his current research is focused on the use of different media to teach and communicate mathematics to diverse audiences.