Question Can we perceive relations? For example, if I have a cup of coffee I can perceive the cup as white, round, hard, and shiny; and the coffee as liquid, brown, hot, and delicious; but the relation in has no color or visual size or shape, and I cannot touch it, hear it, smell or taste it --- so how can I perceive it? It's tempting to say that I cannot perceive it because it isn't real --- but if it isn't real then how could I drink the coffee? The similarity between two oranges, the direction of a train whistle, the relative brightness of the sun and the full moon ... There are countless empirical relations that can/cannot be perceived. How come?

Accepted:
March 2, 2006

Comments

I'd suggest that this puzzle is largely a linguistic one. Consider the relation being larger than. Can one perceive that relation? There's a temptation to say that one cannot perceive the relation itself, because the relation itself "has no color or visual size or shape", and so on and so forth. And maybe that's so. Ask a metaphysician. (Of course, what answer you get will depend upon which metaphysician you ask!)

But the examples with which you began suggest a different question. Can one perceive that one thing is larger than another? Here, it seems to me, the answer is clearly that one can. We perceive that kind of thing all the time. But how can we perceive the relation if we can't perceive the relation itself? The answer, I think, is that this question is just confused. What we perceive is that the objects are so related. Perception, as people sometimes put it, has propositional content, and relations figure in these contents. One might yet wonder how it is that we manage to perceive such things as that the coffee is in the cup. That, I take it, is a question for a psychologist more than for a philosopher, but certainly part of the story is that you can perceive where the coffee is and you can perceive where the cup is, and on that basis your brain might come to have a view about the relation between the coffee and the cup, which view is delivered to you in perceptual experience.

Perhaps someone else here would be able to recommend a place to start if you were interested in the empirical literature on such issues. There has, for example, been quite a lot of empirical work on the perception of causal relations.