Climbing on ice and rock requires the same niceties of balance, of avoiding objective danger, of maintaining a margin of safety. But ice adds a few complications. The margin must be greater—the dangers are different, as are the mechanical aids, whereas methods of correcting errors in judgment are less sure. And where the rock-climber must rely on nature's fortuitous placing of holds and ledges, hoping that he can put the jigsaw pieces together into a complex route, the ice-climber needs only the proper surface; if his technique is good enough, he can cut holds, belays, even bivouacs where he needs them.
