Truthmakers and Time

From Time and Realism: Metaphysical and AntiMetaphysical Perspectives, pgs. 20-22:

Note, in passing, that the term “token” is used here, and will continue to be used throughout the book, to denote something to which a specific date can he attached—an occasion on which someone speaks, prints, writes, reads, or thinks a certain sentence…

Returning to the tensed and tenseless accounts of the truth of “The destruction of Pompeii by Vesuvius is an event of the past,” the two accounts are alike in that for both the relevant linguistic entities are tokens, rather than types of sentences. Types of tensed sentences do not have determinate truth-values: “Today is Monday” is true on some occasions and false on other occasions. The same holds of “The destruction of Pompeii by Vesuvius is an event of the past.” Some of the tokens of this sentence are true, others are false. But each of these tokens has a single fixed, unchanging truth-value. It cannot be both true and false. Again, this is true on both accounts. The difference between the tensed and tenseless accounts is that in the former truth conditions are nonrelational, whereas in the latter they are relational in the following sense. The tensed truth condition on which a token of “The destruction of Pompeii by Vesuvius is an event of the past” is true is the nonrelational condition that the event in question is past. In specifying this condition no mention is made of the temporal relationship between the event and the token whose truth condition this condition is. That is, this relationship does not enter into the condition. In contrast, this relationship is integral to the tenseless truth condition of this sentence: a token of the sentence is true on the condition that the event in question—the destruction of Pompeii by Vesuvius—stands in the temporal relationship of being earlier than the tokening of the sentence.

Mellor’s crucial observation is that to insist, as McTaggart’s opponents do, that tensed conditions constitute truth conditions for tokens of tensed sentences is to imply that tokens can be both true and false. For, as time flows, tensed conditions change and with them the truth-values of tokens describing these conditions. For example, up to the moment of Vesuvius's eruption, the tensed conditions that obtain are that this event is future, and these conditions establish the falsehood of all tokens of “The destruction of Pompeii by Vesuvius is an event of the past.” After the eruption, the tensed conditions that obtain are that this event is past, conditions in light of which all tokens of “Vesuvius erupted in the past” are true. It turns out that if McTaggart is wrong, that is, if the tenses are real and time flows, then each token of “Vesuvius erupted in the past” is both true and false, a blatant contradiction, the contradiction McTaggart uncovered.

Of course, it cannot he objected that these tokens have different truth-values at different times. Tokens, to repeat, have determinate, unchanging, truth-values. The other escape is to correct the account so that those tokens of “Vesuvius erupted in the past” that occur before the eruption are assigned “false” as their truth-value, and those that occur after the eruption are assigned “true” as their truth-value. This move, indeed, fixes the truth-values of tokens and removes the contradiction. But it concedes everything to the tenseless theorist, and is tantamount to endorsing the tenseless, relational token-reflexive account.

If I understand this correctly:

To assert that the token “Vesuvius will erupt [in the future]” is true if one utters, thinks, writes[, etc.] the token earlier than the eruption of Vesuvius would be to assert a tenseless truthmaker for the tensed sentence. More generally, the assertion that some token p referring to some event in the {past, present, future} is true if one utters, thinks, writes[, etc.] the token {later than, simultaneous with, earlier than} the event conveyed by p would be to assert that truthmakers are tenseless. The B-series view is coherent.

On the other hand, the token “Vesuvius will erupt [in the future]” is both true and false if there are tensed truthmakers. Why? Because if time flows, Vesuvius’ eruption, which was once future, becomes present and then past. An irreducibly tensed token, then, will bear the truth values for each of these tensed truthmakers, i.e. the token will be both true and false, a contradiction. It will not do to say that the sentence is true when uttered when the event is future and false when uttered when the event is past because what is under consideration are tokens, not types, of sentences. What is under consideration is an actual instance in which “Vesuvius will erupt [in the future]” is uttered. So the A-series view is incoherent.