Principles Of Human Knowledge - pg. 104

It is indeed an opinion strangely prevailing amongst men, that houses, mountains, rivers, and in a word all sensible objects have an existence natural or real, distinct from their being perceived by the understanding. But with how great an assurance and acquiesence soever this principle may be entertained in the world ; yet whoever shall find in this heart to call it in question, may, if I mistake not, perceive it to involve a manifest contradiction. For what are the forementioned objects but the things we perceive by sense, and what do we perceive besides our own ideas or sensations ; and is it not plainly repugnant that any one of these or any combination of them should exist unperceived?