It is not God's will that what he creates for man's benefit and what he has given us should remain hidden... . And even though he has hidden certain things, he has allowed nothing to remain without exterior and visible signs in the form of special marks- just as man who has buried a hoard of treasure marks the spot that he may find it again.A knowledge of similitudes is founded upon the unearthing and decipherment of these signatures. It is useless to go no further than the skin or bark of plants if you wish to know their nature; you must go straight to their marks- 'to the shadow and image of God that they bear or to their internal virtue, which has been given to them by heaven as a natural dowry,... a virtue, I say, that is to be recognized rather by its signature'. The system of signatures reverses the relation of the visible to the invisible. Resemblance was the invisible form of that which, from the depths of the world, made things visible; but in order that this form may be brought out into the light in its turn there must be a visible figure that will draw it out from its profound invisibility. This is why the face of the world is covered with blazons, with characters, with ciphers and obscure words- with 'hierographics', as Turner called them. And the space inhabited by immediate resemblances becomes like a vast open book.