[87] Now of success in this matter these will be the most established foundations: to give to things without form shape [55] [56] and character, and to distinguish each thing separately with distinct outlines, lest, if they become shaken and lame (though fixed on firm foundations,) and if they have assumed a connection with the nature of a quadrangular shape, (for this is a nature always unshaken), they may then, being established steadily like a building of brick, support even those things which are built upon them.