Like a hammer cannot screw in a screw, and a nail cannot cut a board of wood, the human mind cannot make sense of the mindless. A hammer can perhaps smash a screw in, and a nail can perhaps split a board of wood, just like the mind can perhaps consider life, but none of these items or tools fully suit the jobs that they are carrying out here, and thus, will fall short in properly completing them. A kōan embodies this notion.
