The Truth Conditions of Tensed Propositions

I am an A-theorist with respect to the metaphysics of time. An A-theorist is one who believes that there is an objective 'now' or, what amounts to the same thing, that the totality of reality undergoes change. The opposite of the A-theory of time is called the B-theory. According to the B-theory, reality is constant and unchanging. There may be temporal relations between different parts of reality, but reality itself, taken as a whole, is a static block.

There are several reasons why I'm an A-theorist despite the fact that the B-theory is the philosophical fashion nowadays. One argument in particular that seems persuasive to me is this one:

1. There are true tensed propositions.
2. If there are true tensed propositions then there are tensed facts that make those propositions true.
3. Therefore, there are tensed facts. (from 1 and 2)
4. If there are tensed facts then there is an objective 'now'.
5. Therefore, there is an objective 'now'. (from 3 and 4)

Needless to say, this argument is controversial, especially premise 2. Premise 4 is a platitude, a straightforward consequence of the notion of a 'tensed fact'. (The notion of tense has to do with the relation of things to the present or 'now'.)

Premise 1 has been denied by many B-theorists. Bertrand Russell, Willard Quine, and others argued that there are no tensed propositions. The justification for this claim was supposed to lie in the fact that all tensed propositions could be translated salve significatione (without loss of meaning) into tenseless propositions. If that were true, then tense could be safely eliminated.

But during the 1970's and 1980's, in large measure as a result of the work of Richard Gale, B-theorists generally abandoned this strategy. The problem, which Gale and others pointed out, is that tense conveys meaning. For example, it is quite a different thing to be told "A bomb is about to go off (future tense) in the UNLV philosophy department" and "A bomb goes off (tenseless) in the UNLV philosophy department". The former tells me that the bomb has not yet gone off but soon will. (So maybe I should run for cover.) But the latter tells me nothing as to whether the bomb's going off is in the distant past, recent past, present, near future, or distant future. It can't guide my action in the same way because it contains less information. So, pace Russell et al., tense cannot be eliminated without loss of meaning.

Another way to deny Premise 1 is to concede that there are tensed propositions, but deny that any of them are true. I don't know of anyone who has defended this position, but it is a theoretical possibility. One problem with it is that is flies in the face of commonsense. Every natural language known to us has a system of tenses, and speakers of those languages routinely make tensed claims, and many of these claims would be regarded by other competent speakers of those languages as true. Thus, "The Allies won (past tense) WWII" is true; "George W. Bush is (present tense) the President of the U.S." is true; and "The sun will shine (future tense) on the Earth tomorrow" is true. It takes quite a bit of sophistication (sophistry?) to evade the force of commonsense on this point.

Today, the target of choice for nearly all B-theorists is Premise 2. Proponents of the so-called "new" B-theory of time concede that there are true tensed propositions and that they cannot be translated salva significatione into tenseless propositions, but they deny that there have to be tensed facts to make these propositions true. They argue, in other words, that tensed propositions have purely tenseless truth conditions. There are different versions of this strategy (e.g., the "date theory" and the "token-reflexive theory"), but all of them are variations on the same two-part strategy. Given a generic tensed proposition like "It (was, is, will be) the case that E, we generate tenseless truth conditions by

• replacing 'was', 'is', and 'will be' with relations like 'earlier than', 'simultaneous with', and 'later than', respectively
• specifying as the relata of those relations (i) the event spoken of, E, and (ii) a designated time, e.g., this date, the time of this utterance, etc.

For example, on this view, the truth conditions of "Caesar was assassinated" may be given as follows: "Caesar is (tenseless) assassinated earlier than 07/25/2007."

For my part, I don't think this strategy works. (B-theorists, of course, will beg to differ.) As I see it, to claim that "Caesar was assassinated" is to claim that this event has already happened, that it is past. But a claim is true if and only if what is claimed to obtain does obtain. Since the claim is that this event is past, it is true if and only if the event is past. It's being 'earlier than' some date, whether specified referentially (e.g., 07/25/2007) or token-reflexively (e.g., "the time of this utterance"), is not enough, for in neither case does it require the event to be past, as claimed.

Let me put this another way. Because "Caesar is (tenseless) assassinated earlier than 07/25/2007" is tenseless it gives us no information about whether 07/25/2007 is past, present, or future. As I am writing this, I know that that date has just recently become past. But that knowledge comes from outside the tenseless proposition. In and of itself, the tenseless proposition is perfectly compatible with any of three differently tensed propositions:

• Caesar was assassinated.
• Caesar is being assassinated.
• Caesar will be assassinated.
  

If satisfying the tenseless truth conditions suffices for the truth of the first tensed proposition then, by reasons of parity, it should also suffice for the truth of the other two and thus of all three. But it can't. These tensed propositions are mutually incompatible. So satisfying tenseless truth conditions cannot suffice for the truth of any tensed proposition.