Truth and Expectation

Suppose I see a man approaching from a long way off. “That man is pretty tall,” I say to a companion. The man approaches, and we meet him. Now I can see how tall he is. Suppose my companion asks, “Were you right that the man is pretty tall, or were you mistaken?”

“Pretty tall,” of course, is itself “pretty vague,” and there surely is not some specific height in inches that would be needed in order for me to say that I was right. What then determines my answer? Again, I might just respond, “It’s hard to say.” But in some situations I would say, “yes, I was definitely right,” or “no, I was definitely wrong.” What are those situations?

Psychologically, I am likely to determine the answer by how I feel about what I know about the man’s height now, compared to what I knew in advance. If I am surprised at how short he is, I am likely to say that I was wrong. And if I am not surprised at all by his height, or if I am surprised at how tall he is, then I am likely to say that I was right. So my original pretty vague statement ends up being made somewhat more precise by being placed in relationship with my expectations. Saying that he is pretty tall implies that I have certain expectations about his height, and if those expectations are verified, then I will say that I was right, and if those expectations are falsified, at least in a certain direction, then I will say that I was wrong.

This might suggest a theory like logical positivism. The meaning of a statement seems to be defined by the expectations that it implies. But it seems easy to find a decisive refutation of this idea. “There are stars outside my past and future light cones,” for example, is undeniably meaningful, and we know what it means, but it does not seem to imply any particular expectations about what is going to happen to me.

But perhaps we should simply somewhat relax the claim about the relationship between meaning and expectations, rather than entirely retracting it. Consider the original example. Obviously, when I say, “that man is pretty tall,” the statement is a statement about the man. It is not a statement about what is going to happen to me. So it is incorrect to say that the meaning of the statement is the same as my expectations. Nonetheless, the meaning in the example receives something, at the least some of its precision, from my expectations. Different people will be surprised by different heights in such a case, and it will be appropriate to say that they disagree somewhat about the meaning of “pretty tall.” But not because they had some logical definition in their minds which disagreed with the definition in someone’s else’s mind. Instead, the difference of meaning is based on the different expectations themselves.

But does a statement always receive some precision in its meaning from expectation, or are there cases where nothing at all is received from one’s expectations? Consider the general claim that “X is true.” This in fact implies some expectations: I do not expect “someone omniscient will tell me that X is false.” I do not expect that “someone who finds out the truth about X will tell me that X is false.” I do not expect that “I will discover the truth about X and it will turn out that it was false.” Note that these expectations are implied even in cases like the claim about the stars and my future light cone. Now the hopeful logical positivist might jump in at this point and say, “Great. So why can’t we go back to the idea that meaning is entirely defined by expectations?” But returning to that theory would be cheating, so to speak, because these expectations include the abstract idea of X being true, so this must be somehow meaningful apart from these particular expectations.

These expectations do, however, give the vaguest possible framework in which to make a claim at all. And people do, sometimes, make claims with little expectation of anything besides these things, and even with little or no additional understanding of what they are talking about. For example, in the cases that Robin Hanson describes as “babbling,” the person understands little of the implications of what he is saying except the idea that “someone who understood this topic would say something like this.” Thus it seems reasonable to say that expectations do always contribute something to making meaning more precise, even if they do not wholly constitute one’s meaning. And this consequence seems pretty natural if it is true that expectation is itself one of the most fundamental activities of a mind.

Nonetheless, the precision that can be contributed in this way will never be an infinite precision, because one’s expectations themselves cannot be defined with infinite precision. So whether or not I am surprised by the man’s height in the original example, may depend in borderline cases on what exactly happens during the time between my original assessment and the arrival of the man. “I will be surprised” or “I will not be surprised” are in themselves contingent facts which could depend on many factors, not only on the man’s height. Likewise, whether or not my state actually constitutes surprise will itself be something that has borderline cases.