Listening to Susskind's online QM lectures, he has mentioned the "classical spin" of an electron a few times (with an associated magnetic moment), but I didn't think the electron really has a classical spin. Specifically, in Maxwell's equations we only get magnetic fields for moving charges, so I don't see how a point particle like an electron would have a magnetic moment in a classical context if it is at a fixed position in space. The only way I can think of a electron with spin in a classical context would be if you modelled it as some specific charge distribution in a volume and then set that charge distribution spinning. Then add up the magnetic field contributions from all the individual bits of that moving distribution, to achieve a classically model of a spinning electron with Maxwell's equations. But if you did this it would radiate (like a classical electron in the Bohr model should), and I presume would eventually loose its angular momentum and spin to that radiation. Can anybody guess what Susskind may be talking about here?