Hi there -- I've just started looking at the topic of dualities in quantum field theory, and I've hit the wall right at the beginning! Looking at the classic Olive-Montonen paper (from 1977), they show how we get elementary quanta of photon, higgs and heavy gauge boson from the Georgi-Glashow model, and that's all familiar and fine. They then say, however, that these correspond to `classical particles' in the limit that h→0, with the charge and quantities in h-bar held fixed in the process. I have two questions about this: (1) Why do we care about whether or not these quanta correspond to classical particles? Don't we think of particles in terms of field quanta these days? (2) How can we keep quantities in h-bar fixed given that we're taking the limit in which h→0? I'm sorry if these seem like stupid or overly specific questions, but since all the literature on duality seems to begin with M-O duality as the simplest example I thought I'd better get this sorted out at the outset! Big thanks to anyone who can help here.