The camera abstracts the image in the photograph: the philosopher abstracts concepts. A lion and a photograph of a lion: if you rip the photograph, the real lion is left unscathed - the destruction of concepts leaves the world unscathed. The relation between the lion and the photograph might be the relation between the world and concepts: the photograph abstracts the lion - the concept abstracts from the world. Whence comes the concept of a unicorn: if there were no lion, it's photograph would be impossible - yet we have the concept of a unicorn: how does one abstract from that which is not?