Robert Louis Stevenson 
The Art of Writing [EPUB ebook] 

Long essay that begins: 'There is nothing more disenchanting to man than to be shown the springs and mechanism of any art. All our arts and occupations lie wholly on the surface; it is on the surface that we perceive their beauty, fitness, and significance; and to pry below is to be appalled by their emptiness and shocked by the coarseness of the strings and pulleys. In a similar way, psychology itself, when pushed to any nicety, discovers an abhorrent baldness, but rather from the fault of our analysis than from any poverty native to the mind.’