Our fascination with knives isn't too surprising, given that the first recognizable tools, at least 200,000 years old, had decent cutting edges. Stone tools cut very effectively and they are dirt cheap. It's just that the edge doesn't last very long and needs resharpening about every ten minutes or so when you are whittling on a mammoth.

The perfect survival blade for the ETS crowd would be the legendary Green River Knife, made of nondescript steel, but strong enough to decimate the beaver population and conquer a continent. By all accounts it was tough, versatile, and durable, rarely breaking. Of course, if you broke your GRK, you probably didn't get back to tell about it. Anyway, they were among the hottest trade items to Native Americans, speedily superseding stone tools.

End of the history lesson; there will be a quiz on Friday.