Dan Murren commented: “So “nothing” IS something, but does “nothing” continue to exist as soon as there is no one present to experience or conceive it?” The philosophical question he’s referring to is: “Does anything exist independently, apart from human experience?
Locke and other philosophers held that color, taste, smell, sounds, touch–don’t have an independent existence apart from human sensation. These “Secondary Qualities” do not inhere in the things themselves. They reside, rather, in the person.
Colored glasses change the colors we perceive of things, putting your hand in ice then touching something that is room temperature makes it feel hot. If touch and smell and sight were real and independent, they wouldn’t change with changing conditions. On the other hand, Primary Qualities (depth, width—the brute extension of an object—and the motion of an object) do inherently exist apart from human perception, according to one view. They don’t change based on our perceptions or the external conditions.
But nobody is satisfied with a patent answer! Berkeley came along a few years later and said extension and motion and so forth should also be considered Secondary: they exist only in a mind that perceives them. Even Primary Qualities are just our sensory perceptions and nothing else. Take away the perceiving subject, and you take away the sensible world. His famous quote is: “To be is to be perceived.” It helps to realize that we interface with the world via our nervous systems and brains, and we never really see or hear things themselves; we only have our perceptions and our ideas of things: E.g., photons (light) come from a light bulb and bounce off a bowl of ice cream, and enter our eye, and the cones/rods change those photons from the light bulb into electrical impulses which travel through the optical nerve to a portion of our brain where they are further processed. Then, POOF! we have an idea in our head of a yummy bowl of ice cream. We “see” processed photons (from a light bulb) and conclude it’s a bowl of ice cream. Thus the bowl is really more of a subjective idea than an object. Do we actually ever “see” the bowl itself, apart from our idea or perception of it? Berkeley said No Way. The same thing with taste, sound, etc.—they don’t actually inhere in a real way inside an object.
In the modern period (about 1500 to 1800) the issue of whether something exists or not begins to become a question of Epistemology (the study of Knowledge). Over the centuries, two schools developed: Rationalism and Empiricism:
Rationalism says that knowledge of the world can best be achieved by a priori judgment (judgment independent of perception or experience). E.g., you can know, a priori, that 2+2=4 (you don’t have to actually see 2 apples and 2 other apples, then count them and arrive at 4).
Empiricism says that experience is the best source of ideas and knowledge–to know something a posteriori means that you have to verify it with your senses before you can know it. In order to know there are 4 apples in the next room, you have to go look.
Nowadays, most of us agree that Immanuel Kant (Philosophy Pages), more or less, solved this debate. In a sense he answered Dan’s question about something existing or not apart from human experience. But that’s a WNBOW (a Whole Nother Ball of Wax).