By Keith McCafferty Illustrations by Tom McCafferty There's an old Nordic saying: "A man without a knife is a man without a life." The knife is the one essential survival tool. Know how to use a knife and you can spark a fire, whittle the trigger for a deadfall trap, cut saplings to shelter from the storm. Not to mention skin a deer. But how many of us can call on basic knifecraft skills in a crisis? How many of us understand blade design? The right kinds of steel for the right kind of knife? Let's slice to the heart of the matter. Most of us do little with our knives beyond trim our fingernails, fillet crappies for the pan, and field dress the occasional buck. Chances are your knife skills are rusty. But maybe not. By taking this test, you can find out how much you know. More important, you can find out what you don't know. Study up, and you can turn a dull edge into a keen one.