Tuesday, July 31, 2012

The Precondition of Self-Authenticity

I have written in many posts that an omniscient source is a precondition for knowledge, essentially because unless we have access to such a source, the possibility that "the truth value of any proposition is predicated on the truth value of an unknown proposition" (including this proposition) would lead to skepticism.

But isn't this necessarily self-defeating? For I am not omniscient. Is it not possible, then, that the truth value of the proposition in which I assert what the omniscient source is to which I have access is one which could be predicated on the truth value of an unknown proposition?

No. For it is possible for an omniscient source to be self-authenticating. In fact, given that we are not omniscient, it is necessary in order to avoid skepticism. What this means is that while an omniscient source is necessary, it is also necessary that for those who are not omniscient to know anything, the proposition that "it is possible the truth value of any proposition is predicated on the truth value of an unknown proposition" is false.

But since this proposition is false, does that mean an omniscient source is unnecessary after all? Again, no. There is a mutual dependency among the preconditions for knowledge. For example, logic and language are preconditions for knowledge. You can't have one without the other. You can't know what logic is without using language, and you can't know what language is without using logic.

Similarly, I am saying it logically follows that you can't know that an omniscient source is necessary if that source isn't self-authenticating, and you can't know a source is self-authenticating if you did not deduce that from an omniscient source. And you can't know either of these if the alleged source is illogical or doesn't communicate. Etc.

To assert "source x is self-authenticating" without having recourse to an omniscient source which states or implies such falls prey to the possibility (within that worldview) that "the truth value of any proposition is predicated on the truth value of an unknown proposition." Rejection of this too as a possibility falls prey to the same possibility that "the truth value of any proposition is predicated on the truth value of an unknown proposition." These rejections are propositions, after all.

Rather, what saves the possibility of knowledge at this point is precisely having recourse to an omniscient source which, since the source knows all, knows that "the truth value of any proposition is predicated on the truth value of an unknown proposition" isn't, in fact, a possibility. Furthermore, the source is able to communicate such information to men, able because the communication is, among other things, self-authenticating. The need for self-authentication strictly pertains to the need for the possibility of communication from an omniscient source; it doesn't erase the need for an omniscient source.

[I have tried to be as neutral as possible in describing the nature of this "source," though it must be the God of Scripture. For why I would write my post in this way, see the last five paragraphs here.]

Thursday, July 26, 2012

Questions on Time

In recent posts, I’ve criticized the A-series view of time. To be fair, however, I think I should also outline some reservations which have prevented me from whole-heartedly accepting the B-series view of time.

As I understand it, the primary way in which the uni-directionality – a seeming precondition for the intelligibility divine purpose – of the B-series view of time is said to be preserved is by grounding the temporal order on the causal order, a notion which seems to harmonize quite nicely with Christian determinism. Time is the measure of change, not a medium in which change takes place. So, for example, event A is said to be “earlier than” event B because it either is a cause of event B or is simultaneous with a cause of event B.

However, if this is the case, then how can Christians regard the generation of the Son, procession of the Spirit, and creation to be eternal or timeless? For if generation, procession, or creation imply causation, then since the temporal order is grounded on the causal order rather than the reverse, it would seem to follow that these events are temporal: generation, procession, or creation would be later than that which caused them.

What about the incarnation? This is one of the older objections to divine timelessness, if I’m not mistaken. How can the Son be timeless yet act in time (assuming He did)?

I’m certainly not saying these questions have no answers, especially considering the relatively little I’ve read. I’m aware that a few Christian B-theorists have written about time and the incarnation, so it’s quite possible they have considered things I haven’t. The same goes for issues regarding time and causation.

Wednesday, July 25, 2012

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 questionthe 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.