I understand mathematically why it is the case that the **H** must be in the opposite direction to the magnetization of the bar magnet, but I'm not quite sure what this means intuitively. This is due to $\nabla.\bf{H} = - \nabla.\bf{M}$, so $- \nabla.\bf{M}$ acts like a source of "fictional magnetic charge". But if our **H**-field is in the opposite direction to **M** does this then try to reduce the overall magnetization of our bar magnet and realign the magnetic dipoles inside in the direction of **H**? If so, then wouldn't it cause the magnetic dipoles to oscillate left and right all the time? Why do we have bar magnets at all in this case?