I think it is no small attraction in a painter to be able to give a pleasing air to his figures, and whoever is not naturally possessed of this grace may acquire it by study, as opportunity offers in the following manner: be on the watch to take good parts of many beautiful faces of which the beautiful parts are established by general repute rather than by your own judgement, for you may deceive yourself by selecting faces that resemble your own, since it often seems that such similarities please us; ... so therefore choose the beautiful ones as I tell you and fix them in your mind.
Leonardo da VinciOf the four elements water is the second in weight and the second in respect of mobility. It is never at rest until it unites with the sea.
Leonardo da VinciYou should look at certain walls stained with damp, or at stones of uneven color. If you have to invent some backgrounds you will be able to see in these the likeness of divine landscapes, adorned with mountains, ruins, rocks, woods, great plains, hills and valleys in great variety; and expressions of faces and clothes and an infinity of things which you will be able to reduce to their complete and proper forms. In such walls the same thing happens as in the sound of bells, in whose stroke you may find every named word which you can imagine.
Leonardo da Vinci