Was Feynman a Kantian Physicist?
Einstein was!

According to Feynman, the adventure of our science of physics is a perpetual attempt to recognize that the different aspects of nature are really different aspects of the same thing.

Indeed, modern physics is the physics of harmonic ocillators and/or two-by-two matrices, since otherwise problems are not soluble. Feynman wrote many other papers. It would be interesting to combine them into the regime of the above three papers. You may also consider including your own papers.

Y. S. Kim (2006.5.12)

PS. Solving the coupled-oscillator problem is not much different from diagonalizing the quadratic equation

I learned how to do this in high school. You did too. The easiest way to solve this problem is to draw this circle/ellipse figure. You have seen this figure one way or another. These days, it is most commonly used as the logo for the conference series called ICSSUR (International Conference on Squeezed States and Uncertainty Relations). The 10th ICSSUR meeting (2007) will be held in England. The earliest version of this figure is contained in my 1973 paper with Noz on Feynman's physics.

Many of my colleagues are complaining that I know nothing other than harmonic oscillators and digonal or 2-by-2 matrices. True! For this reason, I can do many things they cannot do. If you combine them, you end up with two coupled oscillators. I love coupled oscillators.

Feynman photo: courtesy of the Niels Bohr Library of the American Institute of Physics.