This piece deals with the nature of truth-valued statements which have semantic contents which are said to be “evidence-transcendent”. In less technical terms, the nature of unobservability and observability-in-principle are tackled within an anti-realist versus realist context.
The classic cases are covered: including the doubling in size of the universe, Bertrand Russell's flying teapot, Michael Dummett's organisms in Andromeda, past and future events, electrons, other minds and what it is to be bald.
Within these contexts, we'll also try to clarify what it is to understand statements which have evidence-transcendent content.
The realist position on truth can appear strange, at least prima facie. Take this statement:
“In 607 AD there were precisely one million people with ginger hair in Europe.”
According to the realist, that's either true or false. He may also say that it's determinately true or false (i.e., it's truth is fixed in time).
Similarly for this statement:
“Is is true [false] that Theresa May, at this precise moment, is dreaming about flowers.”
If Theresa May isn't asleep, it's false. That would be easy – in principle – to determine. Though what about if she is asleep at this precise moment? Is it still determinedly true or false that she's dreaming about flowers?
Despite that, it may well be the case that although one takes a realist position on this, one needn't take a similarly realist position on all other domains of discourse. (This is often said of anti-realism, not realism.) More specifically, statements about Bertrand Russell's flying teapot or Dummett's organisms in Andromeda (both covered later) may well be determinately true. Nonetheless, is it automatically the case that a realist should also have exactly the same position, for example, on statements about the future? Perhaps a realist believes that statements about the future throw up problems which aren't encountered in these other domains.
Following on from that, an anti-realist can ask a realist two questions:
i) If you understand the statement “It is true [or false] that that the universe sprang into existence just five minutes ago, replete with traces of a long complex past” [worded by Bob Hale], then how do you understand that sentence?
ii) What gives you the warrant to say that it's either true or that it's false?
The realist may now reply:
What do you mean by the word 'understand' [as in “understand that sentence”]?
A standard picture is that in order to understand p, one needs to understand both p's truth-conditions and then somehow decide whether or not those truth-conditions obtain. So, in the case of the statement about the universe doubling in size, how would the truth-conditions for the universe being the same size differ from the truth-conditions of a universe which has doubled in size? (I'm assuming here that the philosophical puzzle of a doubled universe works. As it is, there are arguments against it.) Secondly, how would someone be warranted (or justified) in saying that the universe has or hasn't doubled in size?
The argument is that if the realist can't answer these questions, then his position is untenable. That is, he doesn't know what he's talking about. Or, less judgementally, he doesn't understand what he's talking about. That means that we have no means of understanding what a realist position on truth (at least as regards the doubled-universe scenario) amounts to.
The Doubled Universe
Since we've just mentioned the doubled-universe scenario, Bob Hale talks in terms of what he calls “chronically e-transcendent statements” . (The 'e' is short for 'evidence'.) He cites the doubled-universe case:
“Everything in the universe has doubled in size.”
As well as:
“The entire universe sprang into existence just five minutes ago, replete with traces of a long and complex past.”
(These statements have been much discussed in philosophy; though not always in the context of the realism vs. anti-realism debate.)
If the universe had doubled in size (so the argument goes), then there'd be no way of telling that it had actually done so. Thus we couldn't say that it has or that it hasn't doubled in size. Nonetheless, isn't it the case that it either has or it hasn't doubled in size? And if that's the case according to the realist, the statement is indeed determinately true or determinately false.
There are many problems for the anti-realist position too; especially if anti-realism is closely tied to acts of verification (or to verificationism).
Take the many unobservable phenomena of science (specifically of physics). Can it be said that statements about, say, electrons are similar in kind to statements about our doubled universe or flying teapots in distant galaxies? Certain anti-realists would say that even though electrons aren't observable, we're nonetheless led to posit their existence because of the evidence supplied by phenomena which are indeed observable. Thus, although electrons are too small to be observed, we're led to them by observable phenomena - plus, of course, lots of theory. (Couldn't the realist argue that he's led to his statements about determinate truth about the unobservable-in-principle by what is actually observable?)
The idea that an electron is posited due to phenomena we can observe (along with theory) is parallel - or additional - to the idea of something's being observable-in-principle.
It could be said that something as tiny as the electron could be observable in principle; except for the large problem that it's deemed to be a “theoretical entity” anyway. That is, besides mathematical structure (as well as theory), there would be nothing to observe even if we could observe it. On the other hand, we can say that a distant something in our solar system could be observed in principle. That may mean that this something isn't a theoretical entity at all. Well, in a sense, it is a kind of theoretical entity in that it hasn't actually been observed. Though being, say, a teapot, it could be observed if we were able to travel to the distant place it inhabits. (Let's forget the science here!)
There's one clear problem for this observable/unobservable opposition. This is that there isn't always (or never) a clear dividing line between observation-statements and theoretical statements. That can be because observation-statements involve theory and theoretical statements involve (elements derivable from) observation. Still, whatever problems there are here, they're not as problematic as those statements about unprovable mathematical statements; and certainly not as problematic as our doubled-universe scenario.
A similar problem arises for anti-realism when it comes to other minds. We can't observe the goings-on in other people's minds. Nonetheless, like electrons, we're led to acknowledge other minds because of the things we can indeed observe. However, in this case we still need to accept that behaviour (including speech and writing) isn't conclusive evidence for other minds.
There are many problems thrown up by other minds. Behaviourism, for one, was/is one response to these philosophical problems. And that's why certain types of behaviourist relied exclusively on behaviour (whether physical or verbal behaviour) in their experiments and musings. That meant that other minds ceased being a problem for behaviourists because minds in effect didn't (really) exist. Or, at the least, behaviourists believed - at one time - that the mind wasn't a fit subject for science.
Is John Bald?
There's also the problem of statements which involve vague concepts or references to vague states-of-affairs (if there can be such a thing!). Take the well-known case of whether a certain person is bald.
To clarify with a statement: “John is bald.” This can certainly be said to have truth-conditions (which certain earlier examples didn't have). Nonetheless, in a certain sense, truth-conditions don't really help here. That is, we have access to John and to John's head. What we don't have access to is whether or not it's true or false that he's bald. (I'm taking it here that someone can be bald even if they have a few hairs left.) Since it's already been said that truth-conditions aren't the problem, then perhaps we do have a problem with the “vague predicate” that is “bald”.
Here we encounter problems covered by a sorties paradox. Can we ignore them for now? Perhaps we can. It can be said, for example, that we can make a stipulation as to what makes someone bald. (This is deemed to be problematic if taken as a sorties paradox.) We can say that anything less than 100 hairs constitutes baldness in a given male. Consequently it can be said that it's determinately true that John is bald or not bald (i.e., post-stipulation).
What if we accept the sorties paradox? Then we'd be unable to decide (care of truth-conditions or anything else) whether or not John is bald. Nonetheless, the realist, yet again, would argue that it's a determinate fact which makes it the case that either John is bald or John isn't bald. The problem is that if we accept the paradox, we can't know either way.
Michael Dummett, for one, had a problem with this realist conclusion.
In terms of the word “bald”, that would mean that our use of words like that would have “confer[red] on them meanings which determine precise applications for them that we ourselves do not know”. Basically, that would mean that the world tells us if John is bald or not. Or, at the least, the world (including John's head) determines the truth or falsity of the statement “John is bald”. In addition, the world determines the truth regardless of whether or not we can ever determine it to be true or false. Yet surely whether or not someone is bald is something to do with what we decide. The world has no opinion on this or on anything else.
Still, this sorties paradox has an impact on the nature/reality of baldness even if we accept a conventional stipulation about baldness. That is, the logical process which leads from having, say, 1000 hairs to having a single hair is still ultimately paradoxical. That is, step by step we can move from the statement “A man has a thousand hairs is not bald” to the statement “A man with three hairs is not bald” without a hiccup.
Another way of looking at this is to say that if the realist is correct, then any indeterminacy there is has to do with our vague predicates or vague statements, not the world itself (or with John's baldness).
The Teapots/Organisms of Andromeda
Michael Dummett offers us this statement:
“'There are living organisms on some planet in the Andromeda galaxy.'”
That statement, according to Dummett's realist, is “determinately true or false” .
In response, the anti-realist adds an extra dimension to this case in terms of the aforementioned idea of observability-in-principle. Dummett expresses the anti-realist's (as well as, I suppose, the realist's) position in this way:
“'If we were to travel to the Andromeda galaxy and inspect all the planets in it, we should observe at least one on which there were living organisms.'”
Basically, because the science and the practicalities are so far-fetched in this case, we can't do anything else but forget them. In other words, we need to give the anti-realist the scientific benefit of the doubt. The problem here, though, is that if we give the anti-realist the benefit of the doubt about this currently unobservable situation (which is nonetheless supposedly observable-in-principle), then we can - or must – do the same in the countless other cases of unobservable phenomena in science (particularly in physics). Having said all that, these provisos may not be to the point here.
In any case, if the aforementioned organisms are observable-in-principle, then perhaps they can't be (fully) theoretical entities. Or, less strongly, if the Andromeda organisms are theoretical entities at the present moment, then they needn't remain theoretical entities simply because they can be observed in principle. (Though, again, perhaps the atomic and subatomic world may one day be observed; though not if the entities concerned are simply “theoretical posits” and/or mathematical structures.)
Statements About the Future
Dummett also brings up another example of something that's unobservable-in-principle: a future event. How can we deal with truth-valued statements about future events?
My prima facie position is twofold.
i) Such statements are neither true nor false. ii) If such statements are neither true nor false, then they serve little purpose.
The realist believes that statements about future events are determinately true or false. According to Dummett, the realist believes that
“there is [ ] a definite future course of events which renders every statement in the future tense determinedly either true or false” .
I find realism towards statements about the future even more difficult to accept than realist claims about other domains. I would agree with Dummett when he says that the only way that a future-tensed statement can be true or false at this moment in time would “only [be] in virtue of something that lies in the present”. This is surely Dummett hinting at some form of determinism in that what is the case at this moment in time will have a determinate causal affect on what will be the case in the future. (Try to forget arguments against determinism here; as well as references to quantum mechanics, backwards causation, action-at-a-distance, etc.)
Let's take that deterministic position to be the case. That is, a future-tensed statement is true or false at the present moment in time because of what is the case at the present moment in time. That's the case even though the event referred to is in the future. That's fair enough; though it's clear that the realist would have no way of knowing whether or not it's true or false at the present moment. Nonetheless, we've already seen that the realist happily and willingly accepts his position of epistemic deficiency.
Instead of using the word “determinism”, Dummett talks about “physical necessity” instead.
Dummett picks up on an interesting consequence of what was said in the previous paragraph. What the realist must do, Dummett argues, is tell us what are the truths about the statement (or situation) at the present moment in time and how these truths bring about the truth of a statement about a future event. That means that only known truths at the present moment can contribute to truths about future events – at least within this context of “physical necessity” or determinism.
Dummett spots a double problem with the realist's position here. The realist can't determine the present-time truths which would bring about truths about the future. And, by definition, he can't determine - as a consequence of this - a statement about the future that's true at the present moment. That means that although the realist acknowledges his lack of a means to determine the truth of a statement about a future event, he hasn't even got a way of determining the present-time truths which will determine - or cause by virtue of physical necessity – the truth of statements about future events. Thus, in order to make sense of his realism, the least we should expect from the realist is the truths of statements about current situations which would cause - or determine - the truths of statements about future events. Without all that, realism towards statements about the future make little sense.
Dummett, Michael. (1982) 'Realism'.
Hale, Bob. (1999) 'Realism and its Oppositions'.