Fears of out-of-control A.I. have reached a boil over the last few weeks, and several industry executives have called for a coordinated slowdown of A.I. development. But if our goal is to control A.I. — and that should be our goal — slowing down isn’t enough. We need to stop the labs from doing something they’re already on the cusp of doing: recursive self-improvement, or handing over the training of A.I. models to A.I.