1. According to Berkeley’s famous theory of perception, we see, feel and otherwise perceive nothing but ideas; the whole of the sensible world with its trees and rocks, sun and stars, consists of nothing but idea sequences. The oddity of the consequence, that we eat, drink and clothe ourselves in ideas, seems to have discredited this theory for the first two hundred years. But in this century, the theory has been applauded for its elegant economy and the daring way it cuts off speculation about the existence and nature of the sensible world. Many other early modern philosophers regarded sensory ideas as only the means by which we perceive other sorts of things; for them, ideas were instruments which, even if fully known in themselves, offer at best partial knowledge of objects that exist in the sensible world. Berkeley’s stunningly simple move is to identify objects we apprehend by sense with aggregates of ideas, while still maintaining that ideas are fully accessible to the mind that has them. This is inter alia a thesis about the intentional objects of perceptual states. We do not perceive objects by means of ideas, because ideas do not represent other things. By identifying ideas and sensible things, Berkeley robs minds of cognitive access to perceptual objects that are not fully accessible to consciousness.