This chapter begins with Faraday’s law, which states that electromotive forces power everything by virtue of the charge e of an electron, and introduces spinmotive forces which reflect the magnetic moment of an electron. This motive force reflects the energy conservation requirements of the spin-torque transfer process that is at the heart of spintronics. The Stern-Gerlach experiment that used spin-dependent forces established the existence of spin. It is shown here that conservative forces would exist even if an electron was not charged, and do exist for uncharged excitations, such as magnons or phonons. Such forces are especially important in ferromagnetic materials where the spinmotive force commonly drives an electronic charge current due to the higher mobility of the majority electrons.