The Material World

For Berkeley, the material world is a strange and alien place. A world of matter, he argues, is colorless, invisible, silent, and devoid of any shapes or sizes. In other words, this material world is so strange that we cannot even conceive what it would be like. One of Berkeley's principle arguments is that this material world can therefore not give rise to the vibrant, sensual world that we experience, and so we have no reason for thinking that this alien world really exists beneath our experiences.

The World of Ideas

In contrast to the material world, Berkeley believes that all the ordinary things we know, such as tables, trees, or books all exist in the world of ideas. This world of ideas is entirely dependent on being perceived; it cannot exist independently of a mind. Throughout the dialogues, Philonous and Berkeley try to show...