>>467435Any axe or knife can be roughly sharpened with any flat stone.
It's a very difficult choice between the saw and the axe. When crosscutting the saw is absolutely superior to an axe, but that's all the saw can do. The axe is practically indestructible and it can be used as a knife or as a chisel. It can also be used to cut down huge trees (maybe you need to cross a stream or whatever)
When travelling light, the saw will do. If not and your life depends on one tool, there is no replacement for an axe.
