this reminds me of a question that I'd like to ask. as a chemist, my view of quantum mechanics is that it is a useful tool to give the right answer for spectroscopy calculations and to make a model of complicated molecules so that we can pin down some parameters with instruments, then get the whole molecule's structure. however, i keep reading on some book reviews at Amazon that the "core of quantum mechanics is not the wavefunction, but the state". What is that supposed to mean? I never paid attention to the "philosophical" meanings of quantum mechanics. All that mattered was knowing how to calculate the wavefunction for various boundary conditions and knowing how to use them. that was until I took a look at the first few pages of Desai's book and didn't actually see many wavefunction symbols in there. this is important news to me because i'm entering a MS in physics soon and don't want to slam into a brick wall due to "learning QM wrong".