A knife is a great tool to have if you're making a cutting board for your fish, it's a great tool if you're making kindling, it's a great tool if you're making a bow drill. You don't always have a knife. You should, but if you don't, you can make the same tools out of stone or bone or antler. It's been done for a long, long time. Not so much anymore. I have an antler, I have a rock. Between the two of these, we can make a great cutting edge.
And there's three or four different types of stone I have here. I have some obsidian, which is a volcanic stone. I have some flint, I have some chert. All those are great stones for throwing a really sharp edge. That's what we're doing to try to do here, is throw a sharp edge by banging on the stone and getting a flake. Let's see, we'll try this one. I now have very sharp knife here, very sharp knife here. This'll easily open up, cut, and gut my fish, skin a deer, or do any cutting needs that I might have. In fact, this is a piece of deer hide, a piece of leather. And to show how sharp these edges are, I can just take this and slice through it really easily. So leather's no problem for it, fish shouldn't be a problem for it.
Beyond that, we can improve these and make them sharper, or give them a handle, which turns them into a knife. So if I wanted to make a handle for this, I could stick it into a piece of wood that I've split, like so, take a piece of cordage, throw this on here, and wrap it, pull it really tight so that it's holding it. I wrap this around and around. I'm going to get a good, nice, tight bite. So I've wrapped it in cordage and I'm going to tie it off. This gives me a nice, tight grip on this stone, so that when I go to cut with it, it'll hold. I've got a couple wraps on here and I'm just tying this off. I'm going to pull it tight again. So I've taken a piece of obsidian, thrown a nice edge by striking it and breaking it off of a big chunk.
Actually, I threw a couple of edges. By "throwing edges" I mean making a sharp piece that you can use either with a handle by wrapping it, using it as a knife, or by having a chunk that you can hold in your hand and use as a blade. Those'll work for skinning animals, for cutting wood, whatever you like.