The applicability of mathematics as a philosophical problem

The semantic applicability of mathematics: Frege's achievements

The descriptive applicability of mathematics

Mathematics, analogies, and discovery in physics

Pythagorean analogies in physics

Formalisms and formalist reasoning in quantum mechanics

Formalist reasoning: the mystery of quantization

Appendix A. A "nonphysical" derivation of quantum mechanics

Appendix B. Nucleon-pion scattering

Appendix C. Nonrelativistic Schroedinger equation with spin.