A bearing must (1) support a loading force (for example, the weight of a rotor) and (2) provide a force gradient (a restoring force) to hold the rotor in position. Permanent magnets can support weight (in a conventional way, without eddy currents), and without creating destabilizing force gradients, but the Earnshaw theorem precludes achieving stability by this means. Eddy currents can provide a stabilizing force gradient without applying a force at the operating position (for example, when a shaft is centered).