his argument is: "(1) We perceive ordinary objects (houses, mountains, etc.). (2) We perceive only ideas. Therefore, (3) Ordinary objects are ideas."

Berkeley's claim that matter does not exist is in opposition to the materialists. "If there were external bodies, we couldn't possibly come to know this; and if there weren't, we might have the very same reasons to think there were that we have now": "A thinking being might, without the help of external bodies, be affected with the same series of sensations or ideas as you have." Berkeley