Giorgio Vasari, Lives of the Most Excellent Painters… (1850)
“ Leonardo, with his profound intelligence of art, commenced various undertakings, many of which he never completed, because it appeared to him that the hand could never give its due perfection to the object or purpose which he had in his thoughts, or beheld in his imagination; seeing that in his mind he frequently formed the idea of some difficult enterprise, so subtle and so wonderful that, by means of hands, liowever excellent or able, the full reality could never be worthily executed and entirely realized. ”
