If you’d like to understand what philosophers of mind are vigorously, and sometimes heatedly, discussing, it’s important to understand qualia. Qualia rhymes with Somalia and the singular is quale, pronounced qua-lay or qua-lee. Although it may be an unfamiliar word, it’s a fairly simple idea. Qualia are the qualities of sensory experience. Here’s a list of examples from my book, Your Living Mind: The Mystery of Consciousness and Why It Matters to You (p. 73):

❁ Color experiences – pale pinks, bilious greens, the electric blue of a peacock’s feathers

❁ Auditory phenomena – frog chirps, fingernails on a chalkboard, the rumble of thunder

❁ Smells – garlic, cigar smoke, sizzling fajitas

❁ Tastes – popcorn, overripe bananas, kung pao chicken

❁ Tactile qualia – paper cuts, rib-tickles, foot rubs with warm lotion

❁ Internal sensations – spine-tinglings, mal de mer, the overwhelming rush of an orgasm

Think about your own vivid sensory perceptions – the snap of firecrackers on July 4th, the scent of oranges, the flavor of peppermint ice cream. Each of these perceptions is experienced as a quale, a special quality that is difficult or impossible to describe. How would you explain the smell of rotten eggs, for instance, to someone who has never been able to smell anything? “Well, umm … it’s just … like that. It has a certain quality that I can’t put into words.”

Unfortunately, discussions about qualia are confusing and contentious, and part of the problem is the crazy-quilt complexity of scholarly terminology. “It is hard to find a description of qualia with which two (let alone all) philosophers would agree …”* In any case, it’s hard to explain how sensory qualia such as pains, tastes, and color experiences could exist within a brain.

We describe some aspects of experience quantitatively. I am now visually experiencing two drinking glasses on my desk and three books. The bigger glass seems about 25% larger than the smaller one, and one book looks twice as far away as the other two. But we wouldn’t say red is twice as low as pink or that blue is a little faster than green. We can compare colors in terms of lightness and darkness, but the quality of the color itself is just its own quality, period. Similarly, the sound of a flute has a special quality, and we aren’t sure how to speak of it quantitatively. A musical tone vibrates at a certain number of cycles per second, so we can talk about a sound wave in quantitative terms, but that’s not a sound-experience. To understand what all the fuss is about, we need to understand that qualia are the qualities of our experiences. If experiences are brain events, we need to understand how the qualities that we experience relate to the quantities that science investigates.

Make sense? If not, send me a question or comment and I’ll reply.

Roger Christan Schriner

* Fred Dretske 1995, p. 73.


Where Are Colors?

I’ll now return to my series on mysteries of consciousness, and next on my list is the puzzle of qualia. To put it very briefly, qualia are the qualities of experience, and I’ll begin by talking about a kind of qualia that is especially vivid and interesting, the qualities of our color-experiences.

Although colors are one of the most widely discussed features of consciousness, it’s hard to know where they are actually located. Think of a bright yellow lemon, for example. When scientists examine the brain, they find grayish neurons, and when they examine the fruit itself, they just find a lot of molecules in motion – no color at all. So if we find no colors on the lemon, and no colors in the brain states that occur when we see the lemon, where is the experience that we call “yellow?”

Of course it seems as if colors are on the surfaces of objects, as if every speck of matter sports a paint job, but is that really so? Here are six ways of thinking about this problem:

  1. Colors are surface properties of physical objects. They are not inner experiences.
  2. Colors are inner experiences. Strictly speaking, it is a mistake to say that objects are colored.
  3. “Color” is a word for two different things – features of the surfaces of objects and color-experiences within the mind.
  4. Colors are one thing, located in two places – the surfaces we see and our experiences of those surfaces.
  5. Colors are whatever cause us to be in states that we refer to as colors. You could have a state that you call “seeing purple” on many different occasions, and each time it might be caused by something different.
  6. Colors don’t exist.

I accept option 2, and I’m also comfortable with 3 as long as we remember that surface colors and experienced colors are quite different. But it’s hard to override our common-sense view that “yellow” is both out there and in here, unproblematically one and the same. In any case, one of the deep mysteries of consciousness is the fact that experience seems to have certain qualities that we cannot locate anywhere in the physical world. More about that next time.

Roger Christan Schriner