Modal Matters – Page 8 – Maverick Philosopher

Whether Jesus Exists Necessarily

Lukas Novak comments by e-mail:

You list the following propositions in your post, Christology, Reduplicatives, and Their Truth-Makers:

1. The man Jesus = the 2nd Person of the Trinity.
2. The 2nd Person of the Trinity exists necessarily.
3. The man Jesus does not exist necessarily.

and then say that "each of these propositions is one that a Christian who understands his doctrine ought to accept." And then you develop a way how the (quite obvious) inconsistency could be explained away.

What I want to point out is that in fact the third proposition most certainly is not something that a Christian who understands his doctrine ought to accept. Quite to the contrary!

There is more to Dr. Novak's e-mail than the above excerpt, but it may help if I give an explicit argument for (3):

4. God is a necessary being: he exists in every possible world.

5. God's creation of a physical universe is a libertarianly free act: there are possible worlds in which God creates a physical universe and there are possible worlds in which he does not. So, although God exists in every possible world, he does not create in every possible world.

6. The existence of a physical universe and of each physical thing in it is contingent. (from 5)

7. Jesus is a man (a rational animal) born in Bethlehem of Mary, etc.

8. Animals, rational or not, are physical denizens of the physical universe.

9. Jesus is a contingent being. (from 6, 7, 8)

10. That which exists contingently (in some but not all worlds) does not exist necessarily (in all worlds). (Self-evident modal principle)

3. The man Jesus does not exist necessarily. (from 10)

This appears to be a 'knock-down' argument. Surely, (4) and (5) are propositions an orthodox Christian must accept. (6) follows from (5). No orthodox Christian can deny (7). (8) is an analytic truth. (9) is a valid consequence of (6), (7), and (8) taken together. (1) is a self-evident modal axiom. (3) follows directly from (10).

I suggest that this crystal-clear argument is more worthy of acceptance that the obscure doctrine of supposita with which Novak attempts to rebut (3).

Conceivability, Possibility, Self, and Body

A reader sent me the following argument which he considers a good one:

1. It is conceivable that I exist without my present body (or any part of it).
2. Therefore, it is possible that I exist without my present body (or any part of it).
3. Therefore, I have a property P that my body does not, namely, being such that possibly, I exist when my body (or any part of it) doesn't.
4. Therefore, I am not my body (or any part of it).

The argument as it stands is enthymematic. The inferential move from (3) to (4) requires an auxiliary premise, one which is easily supplied. It is the contrapositive of the Identity of Indiscernibles, and so we can call it the Discernibility of the Diverse, to wit: If two things differ in respect of a property, then they are numerically diverse (not numerically identical). That is a rough formulation, but it is good enough for present purposes. With the assistance of DD, the move from (3) to (4) is unproblematic.

I should think the move from (2) to (3) is also unproblematic. The inference from (1) to (2), however, puzzles me and troubles me. I accept the conclusion: I cannot for the life of me see how I could be strictly and numerically identical to my body or any part of it. So I would like the above argument, or a reasonable facsimile, to be valid. But I stumble over the move from (1) to (2). To validate this inference we need some such principle as

CEP. For any proposition p, conceivably p entails possibly p.

CEP is what I want to discuss. The possibility in question is not epistemic but real, and is that species of real possibility called broadly logical or metaphysical. Now here is a reason why I have doubts about CEP. I accept that there is an Absolute. Now any decent Absolute (the One of Plotinus is a good candidate as is the God of Aquinas) will be a necessary being, one whose possibility entails its actuality. An Absolute, then, cannot not exist if it exists: it either exists in every possible world or in no world. To prove that an Absolute exists all I need is the premise, Possibly an Absolute exists. I may think to infer this proposition from Conceivably an Absolute exists, by way of CEP. Unfortunately, it seems I can just as easily conceive of the nonexistence of a an Absolute. To paraphrase Hume, whatever I can conceive as existent I can just as easily conceive as nonexistent. We can call that Hume's Existence Principle:

HEP. Everything (concrete) is such that its nonexistence is conceivable.

If HEP is true, then every being is contingent. But if CEP is true, then at least one being is noncontingent. This shows that either CEP is false or HEP is false. Since I am strongly inclined to accept HEP, I have doubts about CEP.

Clearly, much depends on what we mean by 'conceivable.' Trading Latin for Anglo-Saxon, to be conceivable is to be thinkable. But since there is a sense in which logical contradictions are thinkable, we must add: thinkable without broadly logical contradiction. By whom? The average schmuck? Or the ideally penetrative intellect? If an ideally penetrative intellect examines a proposition and detects no broadly logical contradiction, then there will be no gap between conceivability in this sense and possibility. But our intellects are not ideally penetrative. Suppose a person reads and understands Zorn's Lemma, reads and understands the Axiom of Choice, and then is asked whether it is possible that the first be true and the second false. He examines the conjunction of Zorn's Lemma with the negation of the Axiom of Choice and discerns no contradiction. So he concludes that it is possible that the Lemma be true and the Axiom false. He would be wrong since the two are provably equivalent. This shows, I think, that for intellects like ours one cannot in general validly infer possibility from conceivability.

Returning to our opening argument, I would say that it is plausible and renders dualism rationally acceptable. But it doesn't establish dualism. For the move from (1) to (2) is questionable.

What is to stop a materialist from running the argument in reverse? He denies the conclusion and then denies (2). If you insist that your non-identity with your body is conceivable and therefore possible, he tells you that it only seems so to you, and that seeming is not being. Or else he rejects CEP

A Modal Fallacy to Avoid: Confusing the Necessity of the Consequence with the Necessity of the Consequent

No one anywhere can utter 'I am talking now' without saying something true. Indeed, that is necessarily the case: it doesn't just happen to be the case. Letting T = 'I am talking now,' we can write

1. Necessarily, for any speaker S, if S utters T, then T is true.

But it would be a mistake to infer

2. For any speaker S, if S utters T, then T is necessarily true.

The same goes for 'I exist now.' It cannot be tokened, in language or thought, without it being the case that a truth is expressed; but it does not follow that the one who tokens it necessarily exists. Its negation, 'I do not exist now,' cannot be tokened in language or thought without it being the case that a falsehood is expressed; but it does not follow that the nonexistence of the one who tokens it is impossible.

Closer to the Grave, Further from Birth

With every passing day we are closer to becoming grave meat and worm fodder. Or dust and ashes. That’s the bad news. The good news is that, with every passing day, one more day has been taken up into the ersatz eternity of the Past & Unalterable.

The medievals spoke of a modality they dubbed necessitas per accidens. Socrates drank the hemlock, but he might* not have: He might* have allowed his friends to arrange his escape from prison. So the drinking was logically contingent. But he did drink the poison, and once the drinking occurred, that fact became forevermore unalterable, and in this sense accidentally necessary.

There is a certain consolation in the unalterability of the past. The old look back upon a sizeable quantity of past and see that nothing and no one can take away what has happened to them and what they have made happen. All of it is preserved forever, whether remembered or not. The terrain of the present may shift and buckle underfoot as one looks to a future for which there is no guarantee. But the past and its accomplishments are in one's sure possession, proof against every threat. It is curious that the mere passage of time should transmute the base coinage of temporal flux into the gold of an ersatz eternity.

Unfortunately, the treasures of the past are preserved in a region both inaccessible and nonexistent — or should I say next to nonenexistent? You will thus be forgiven for valuing the gold in question no higher than iron pyrite.

And herein, in this hesitation, lies the riddle of the reality of the past. On the one hand, the present alone is real, and what is no longer is not. On the other hand, the past is not nothing. Surely it has some sort of reality, and a reality ‘greater’ than that of the merely possible. Kierkegaard existed and so did Regine Olsen. Their engagement existed and so did its breaking off. But their marriage did not exist: it remains a mere possiblity, unactualized and indeed forever unactualizable. Now what is the difference in ontological status between the mere possibility of their marriage and the past actuality of their break-up? The latter is more real than the former, though both, in another sense, are modes of unreality.

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*These are nonepistemic uses of 'might.'

Dave Gudeman on Modality and ‘Antifactuals’

Long-time contributor Dave Gudeman coins the term 'antifactual' and then asks:

So, what are the truth conditions of an antifactual such as

(A) While the tree in my yard boasts 17,243 leaves at time t, it could have boasted 17,244 leaves at time t.

Here are some candidates:

(1) if the history of the tree had been different then …
(2) if the laws of physics had been different then …
(3) there exists a set of propositions S that were true at times before t such that, had each member of S been false, then given the truth of the various laws of physics and biology, an omniscient being could infer [could have inferred] that the number of leaves would be 17,244 at time t.
(4) there exists a set of propositions S that were true at times before t such that, had each member of S been false, then given the truth of the various laws of physics and biology, I can infer [could have inferred] by my normal power of reasoning and prediction that the number of leaves would be 17,244 at time t.

The problem with all of these candidates is that I don't think you can really know that any of them is true, but Peter, Bill et al. seem to be committed to the proposition that humans can know the truth of antifactuals. I can't come up with anything that humans could know the truth of short of the fact that (A) is not ruled out by mathematics or logic. But I've already discussed the problems with that interpretation. [In the portion of Dave's comments that I haven't quoted.] So that's what I mean when I say that I suspect that antifactuals, when used in a philosophical sense as Peter, Bill, et al use them are incoherent. I cannot figure out what the truth conditions of such propositions are. I can come up with several candidates, but none of them seems to be consistent with the usage and with what Peter, Bill, et al have said about modal propositions.

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