“But the arguments foregoing plainly shew it to be impossible that any colour or extension at all, or other sensible quality whatsoever, should exist in an unthinking subject without the mind, or in truth, that there should be any such thing as an outward object.” -from the Principles of Human Knowledge by George Berkeley

In the Principles of Human Knowledge George Berkeley rejects the existence of the external world of matter and purports that everything we experience as thinking beings are nothing more than ideas. Berkeley appeals to our logic and what we know to be true to support his ideology. He argues that everything we know of the world is known through our senses which is known through the filter of our minds. Our perceptions are sense-ideas that are inextricably linked to our experience of what we believe is external to ourselves.

For example, this morning I sprayed on Chanel Allure, a pleasant fragrance which makes me feel feminine, uplifted and peaceful. I remember buying it at the Frankfurt airport in Germany on my way back from Spain two summers ago, as I was trying to spend the rest of my Euro before I went back to the states. The feelings and thoughts associated with the smell of the perfume are all interwoven with the sensing of the perfume’s smell. Even if one were smelling the perfume for the first time, like when I was in the duty-free shop deciding which variety of perfume to buy and spraying what eventually amounted to an obnoxious cacophony of pleasant aromas, my sensory experience was unequivocally wrapped up in feelings and thoughts about the aroma of the perfumes. Pleasant, fruity, flowery, too strong, musky, overbearing, etc. are all ideas which are part of my perception of the perfume’s aroma.

Berkeley would argue that it is impossible to separate the physical smell of the perfume and the ideas that we have about the smell of the perfume because there is no physical smell. What we consider the objective qualities of the perfume: aroma, liquid, color, volume, even chemical composition are not existent in and of themselves. They exist only as ideas in the mind. Since every perception we have of the world is known to us through the mind as ideas, the only world we experience is the world of ideas. That something called matter, which is external to ourselves exists is merely an idea. The redness of a Red Delicious apple is merely a sense-idea. The sweetness of the apple when we bite into it is merely an idea. And a relative one at that.

Berkeley argues furthermore that qualities such as motion, color, smell, taste, size, number, etc. cannot exist without a mind to perceive them, since as we have already discovered these qualities are mental phenomena in-themselves. They are experiences which require consciousness to be known. Without a conscious observer to experience sense-ideas, they would not exist. And since all of our knowledge of so-called “external objects” are sense-ideas, existent only in the mind, there is no reason to think that there are unthinking objects in the world which posses any of these qualities which we know the world by. The qualities, and therefore the objects exist only in the mind.