Ah, but it is an interesting thing, that these things can so seldom be proved. If I were to perform some piece of, hrmf, magic for you, here in this room, you would claim a thousand ways it could have been done. Indeed, those ways might be exceedingly unlikely, but you would cling to them rather than accept the, mmn, the chance that magic, the eternal inexplicable, might be the true agent, and if you were strong enough in yourself, unafraid, unthreatened, here in your own chambers, well perhaps there would be no magic worked at all. It is a subjective force, you see, whereas the physical laws of the artificers are objective. A gear-train will turn without faith, but magic may not. And so, when your people demand, mmn, proof, there is none, but when you have forgotten and dismissed it, then magic creeps back into the gaps where you do not look for it.