"Let the youth once learn to take a straight shaving off a plank, or draw a fine curve without faltering, or lay a brick level in its mortar, and he has learned a multitude of other matters which no lips of man could ever teach him." --John Ruskin, "Time and Tide", 1883 So what are those things that no lips of man could ever teach? Let's start with geometry, and the concepts straight and level. Without seeing or feeling by hand, concepts of math fall beyond the realm that words alone can convey. They are derived from the experience of the real world, shown to us by exercise and example. Then, beyond that, what does one learn from what Ruskin suggests? I could make a list. Some has to do with the mechanics of our own body and our movemen...