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Question Many years ago someone asked a question I'm still unable to answer. I think it falls under 'perception'. I traveled quit a bit and had many interesting experiences as a woman working for a multi-national corporation. While in Pakistan, I met a co-worker's wife. We got along very well and had a great time discussing something we both enjoyed very much - cooking. She turned to me and asked, "What does an avocado taste like?" They just weren't available to her in Lahore. She had seen pictures and read recipes but never had one. I couldn't relate the taste through comparison because avocadoes are unique. I could talk about colour or texture but that didn't satisfy her question about flavour. I asked many people when I got home. The answers all related to texture or colour. I had an interesting disagreement over the answer, "It tastes green." How do you express or talk about flavour without a base to compare against? How can someone share perception without a common experience? Thanks Nadine

Accepted:
April 5, 2006

Comments

That's a great example, and a great question. There are a number of obstacles to conveying the taste of an avocado to another person in words. Some are practical and some are philosophical.

First, even those of us who've tasted avocados will have difficulties recalling the taste when we're not actually tasting it. I bet I could do pretty well distinguishing avacados from other substances in a blind taste-test, but my current acquaintance with the taste is not so determinate right now as I sit in my office trying to conjure it up while drinking water. I would have an easier time describing the taste to your friend if I were currently eating an avocado.

Second, we seem to have no "purely qualitative" language for picking out the way things taste to us "from the inside". By this I mean that all the descriptions we might use seem to make inelimanable reference to some external substance, and then draw comparisons with the taste it typically causes. Even "salty" means something like "tastes similar to the taste of salt". If this is right then your friend will not only have had to have tasted the substances you use in your comparisons, but even this won't suffice if the taste of an avocado is, as you say, "unuique" in the sense that it can't be experienced as built up out of other tastes. (I don't know if this is true of avocados, but I don't think it's true of all tastes: I don't think the taste of chocolate-flavored coffee is unique in this sense, since I think you can reasonably know what it's like to taste it if you've tasted chocolate and coffee.) This point about how we describe tastse leads to a number of philosphical questions.

(1) How do we explain the fact that, as you nicely point out, we might talk about texture or color to get at the taste of an avocado? "Tastes green" seems to me to convey something accurate (though not all that much) about the taste of an avocado. One reason is that green things might tend to taste more similar to one another than to things of other colors, and we are putting avocados in that class. But more likely we're getting at legitimate "inter-modal" connecctions--a trumpet sounds more pronounced or "sharp" compared to other instruments in the much the same way that brilliant red things visually strike us more dramatically than things of other colors. Study of synaesthesiacs suggest that our brain contains neural connections that underly certain connections across perceptual domains. But in any case, our evaluation of sensory experiences seems essentially contrastive, and it's reasonable that we would shape our contrasts in similar ways across domains. There are obviously lingering mysteries here.

(2) We might wonder whether there really is an inter-subjectively stable way that an avocado tastes for you to describe, since after all people differ in the types of taste discriminations they can make. And even if your friend tastes an avocado, and also turns out to label and discriminate tastes just as you do, there's always the worry that in principle your tastes are systematically reversed--that is, the things that taste salty to you taste sweet to her (even though she calls them "salty") and vice versa. Philosphers have thought long, hard and inconclusively about whether this possibility can be squared with the thought that tastes are no more than physical states of the brain. Some argue that this type of "spectrum inversion" isn't genuinely possibile; and that the point about how we describe our tastes shows that we live under an illusion when we think that there's some inner qualitative character to our taste experiences that can come apart from the substances that cause these experiences, and the types of cognitive and behavioral effeccts these experiences cause in us. On this view, "the way an avocado tastes" doesn't get at a purely qualitative feature of conscious experience that we experience with some "inner eye".

(3) In any case, your example and the questions you ask give rise pretty directly to one of the most controversial thought experiments in contemporary philosophy. This comes from the australian philosopher, Frank Jackson, and I'll try to modify it to your example. Suppose that your friend studied and came to know everything it's possible to know (even in a complete, future physicalist science) about the general workings of taste perception--the chemistry of avocados and other substances we eat, the way taste buds work, the way taste experiences are processed in the brain and lead to certain behaviors, and so on. It seems that even given all this knowledge, she might still say "aha, that's what an avocado tastes like" when she has her first taste. And this suggests, perhaps, that there are facts about taste that go beyond the physical, since your friend might come to learn them by eating an avocado even when she knows all the general physical facts that there are to know about avocado tasting. According to this "knowledge" argument, your inability to fully convey to your friend the taste of an avocado reflects not only practical difficulties and limitations of language, but also the fact that tastes are not entirely physical!

This argument has raised so much controversy that the american philosopher, William Lycan, has said of it: "Someday there will be no more articles written about the "Knowledge Argument". That is beyond disupte. What is less certain is how much sooner that day will come than the heat deat of the universe."