The second, which I don't remember a lot about now except that I enjoyed it greatly at the time, was called Stone Work, and basically looked at the issue of building a stone wall. In July 1995 I copied out a shortish section of the book into a journal I was keeping at the time. Here's the extract from round about page 144:
October in the woods is a forced march into the sensory life; I am armed with, let’s see, the capacity to discern shapes, motions, and colours, to perceive smells, hear sounds. I can also touch things, feel their textures, taste them if I dare. But that’s about it, in the way of experiencing the woods. Except, that is, for proprioception, self-sensing, without which I couldn’t get into the woods to enjoy them. Proprioception is the sense that makes the first five work, that fetches pleasure (and pain and everything else) and brings it home to us. It is seldom mentioned except among psychologists, an almost secret capacity that explains a huge part of how we experience the world..
Surgically deafened songbirds were found to sing their songs as well after the surgery as before. (Science can be hideous.) They sing, we must assume, by how the song feels to sing, rather than by how it sounds. (But then any division of the sense is arbitrary. Auditory clicks produce measurable electrical activity in the optic nerve. Are we seeing these clicks? Is the eye hearing them?) To sing by feel rather than sound is to sing by proprioception. The proprioceptors are nerve endings embedded throughout the muscles, tendons, and joints of the body that read and report on relative position of body parts, on movement, loading, acceleration and deceleration. They make the musculoskeletal system the largest sense organ of the body, a receptor as well as an effector. Proprioceptors are the neural devices that weigh and judge and perceive whatever we do with that muscle, from performing eye surgery to hitting high C to levering a two-hundred-pound stone into place in the footing of a wall. They tell us where we are and what we’re doing as we are doing it; they are our connection to the present tense of physical action.
Some of us get very good with our proprioceptors. Those who do are frequently called athletes, or performers. Playing a violin concerto, for example, may be as dazzling a demonstration of proprioceptive capability as man has yet devised. (And oh, by the way, it’s hot in the hall tonight, your fingers will have to rewrite the music to fit the sag of the strings as your performance goes along.) Those of us who don’t get good at proprioception are called spectators.
A group of athletes is asked to rehearse the skills of their sport in their minds alone, without actual movement, while wired to electronic sensors. The sensors indicate that the motionless athletes are actually firing the same muscles, in the same sequence and with the same timing, that they would if they were actually performing the sport. That is, the physical act is in the musculature as well as the mind.
When I do manage to listen to the cries of birds, where I feel it is in my throat – in the place where singing would take place, if I could sing. I can’t fly either, but when I watch bird flight as I do more often than I listen I feel it in my shoulders. I watch with my shoulders. I’m sure that what is so lovely about bird flight is not simply what the optic nerve sends to the brain, but also what the brain sends to the muscle. The flight of birds is so lovely to me precisely because so much more of my sensory capacity is involved than vision. The guitarist listens to music with his fingers. The fingers may not actually be moving, but that’s where the signals are going, are being picked up. I swear it. I’ve watched musicians listening; I’ve seen their fingers twitch.
Proprioception is the connective tissue of the sensory system, the sense that orchestrates the other five, that ties them all together into a coherent representation of the world. It is how one walks, sings, lays stones. It enhances the degree of contact of a kiss. How can we think our pleasures only come through the other five?