The appreciation and insight in a stroll with Clark reminded me of a sentence by Lewis Thomas, who could intertwine unheard melodies and things from the natural world in his musings. ÒIf we had better hearing,Ó wrote Thomas, Òand could discern the descants of sea birds, the rhythmic timpani of schools of mollusks, or even the distant harmonics of midges hanging over meadows in the sun, the combined sound might lift us off our feet.Ó Clark heard such music.