Time, metaphysics of

4. The B-theory and tensed language

In order to bolster the view that the A-theory constitutes the common-sense, or default theory of time, the A-theorist often appeals to the fact that ordinary temporal language recognizes a distinction between past, present and future, and the associated passage of time. It is then argued that we should, barring strong defeating reasons, accept that ordinary language is veridical in this respect. This kind of argument can be seen as a challenge to the B-theorist to come up with strong defeating reasons why we should not accept that tensed language and thought is veridical, but it has also been offered explicitly as a positive argument in favour of the A-theory (Craig 2000).

Early B-theorists (for example, Quine 1964) argued that tensed language, that is, language that appears to locate events somewhere in the A-series, could be eliminated in favour of tenseless language that, instead, locates events in the B-series. So, for example, a tensed sentence such as ‘The first moon landing is past’, uttered in 2009 could be translated into a tenseless sentence such as ‘The first moon landing occurs before 2009’, where the ‘occurs’ is taken as tenseless rather than present tense. This reductionist strategy was intended to establish that, even though ordinary language is tensed, this should not be taken as indicating that temporal reality itself is tensed. Since tensed language can be eliminated in favour of tenseless language, it is not needed for a complete description of reality, so there is no feature of reality that it, alone, picks out. However, this reductionist strategy ultimately failed, as it was found that it is not the case that every tensed sentence can be translated without loss of meaning by a tenseless sentence (Perry 1979). A-theorists took this to show that, since there is some aspect of the meanings of tensed sentences that cannot be captured by any tenseless sentence, there must also be some feature of reality that can only be described using tensed language, namely, facts about the pastness, presentness and futurity of events.

B-theorists, however, argued that, even if tensed language is irreducible, that is a fact about tensed language, not a fact about temporal reality. The real significance of tensed sentences is that some of them are true, so the important question is what is it about the world that makes them true? A-theorists think that tensed facts make tensed sentences true. B-theorists argue that tenseless facts can do the job. This change in strategy on the part of the B-theorists was initially proposed by Smart and Mellor (Smart 1980; Mellor 1981; see also Oaklander and Smith 1994 and Dyke 2002) in terms of the notion of truth conditi ons. They argued that the truth conditions of tensed sentences could be stated in a tenseless metalanguage. The point of this was to show that the conditions that must be met for a tensed sentence to be true can be met by purely tenseless facts. So, even though tense is an irreducible feature of language, the truth of true tensed sentences can be fully accounted for without the need to invoke the existence of tensed facts. Tenseless facts are sufficient to ground the truth of true, irreducibly tensed sentences. For instance, the sentence ‘The first moon landing is past’, uttered in 2009 is true if, and only if, the first moon landing occurs before 2009. So, the fact that the event referred to by a sentence stands in a certain tenseless temporal relation to the time at which the sentence is uttered is a necessary and sufficient condition for the truth of that sentence. More recent statements of this project have been developed in terms of truth makers (Mellor 1998).

It should be noted that neither the translation strategy of the old B-theorists, nor the truth-condition strategy of the new B-theorists for dealing with tensed language, should be seen as a positive argument in favour of the B-theory. No argument whose premises solely concern the nature of temporal language and whose conclusion concerns the nature of temporal reality can be valid (see Dyke 2003 and 2007). Instead, the aim of the B-theorists’ strategy is to show that the existence of irreducible tense in language need not be indicative of the existence of tense in reality. In other words, the B-theorist aims to undermine the A-theorist’s inference (for example, that of Ludlow 1999) from the existence of tense in language to the existence of tense in reality.