My friend Ben Discoe sends this comment:
For many years, my father taught both Zen Buddhism and Japanese carpentry, to the same students, using the same method: having them diligently sharpen their plane blades, slowly, by hand, then diligently planing wood by hand, for long hours, as a meditation in motion.
The work speaks for itself. Just look at the above joint, and imagine the mental discipline and concentration required to perfect this type of work. Read more about it in Paul Discoe's book:
Zen Architecture: The Building Process as Practice