It is interesting how internal, abstract reality is shaped by external experience of the physical, including what we sense through our hands. When someone gets all "bent out of shape" in an argument, we say, "they have lost perspective," or "they are losing their grip." You can read George Lakoff's work on metaphor to come to a better understanding of this.

On a more practical matter, the use of the hands in practical things like woodworking helps in the understanding of much broader reality. A friend of mine, Charlie Futral is in the business of planning delivery of very large objects through the nation's highway system. Charlie was at one time a woodworker and furniture restorer, and he credits his previous work with his development of the spatial sense that allows him to visualize and plan the safe movement of very large objects through their journey prior to their actual departure.

Another metaphor for losing one's rationality over an issue is the following: "he's lost all sense of proportion." We know that proportion refers to the relationship between the length, width and depth of an object. Can it be that the understanding of proportion that comes through the use of the hands can actually extend rationality into abstract thought. Try it and see for yourself. I can tell you about it, but would you believe me? Watch what we are doing to our planet if you care to see what the extraction of human behavior from hands-on reality can do.