From this we are to learn that all created things are crumbs that have fallen from the table of God. Wherefore he that feeds ever upon the creatures is rightly called a dog, and therefore the bread is taken from the children, because they desire not to rise above feeding upon the crumbs, which are created things, to the Uncreated Spirit of their Father. Therefore, like dogs, they are ever hungering, and justly so, because the crumbs serve to whet their appetite rather than to satisfy their hunger.
–Saint John of the Cross (1542-1591)