Assertion and Presupposition: An Argument for a Distinction

1) Someone, such as Sophomore Sam, who asserts that there are no truths does not assert that there are truths.

And yet

2) That there are no truths entails that there is at least one truth.  (Why? Because it is impossible for the first proposition to be true and the second false.)

Therefore

3) If someone S asserts that p, and p entails q, it does not follow that S asserts that q.  (Assertion is not closed under entailment.)

4) Although Sam does not ASSERT that there is at least one truth when he assertively utters the sentence 'There are no truths,' he is in some relation to the proposition that there is at least one truth. I will say that he PRESUPPOSES it.

Therefore

5) There is a distinction we need to make and it is reasonably labelled the distinction between ASSERTING a proposition and PRESUPPOSING  a proposition.  An act of asserting can carry a presupposition that is not asserted.  Sam's act of asserting that there are no truths presupposes but does not assert that there is at least one truth.

If you don't accept this argument, tell me which premise(s) you reject and why.

Comments

[The Bad Ostrich]

Well if p = q & r, and S asserts p, he asserts q and asserts r.

[The Bad Ostrich]

Suppose e.g. that Sam says 'it is a truth that there is no truth'. He has contradicted himself, of course.

[BV]

You are not playing the game, my man. Tell me which premises(s) you reject and why.

Since my argument is so clear, rigorous, and reasonable, you need a good response to knock it out of commission.

[The Bad Ostrich]

It was not clear, then, that I was challenging your premise 3?

Perhaps I should have added that q & r implies q?

[BV]

So you reject:

3) If someone S asserts that p, and p entails q, it does not follow that S asserts that q.

But (3) is plainly true. You will grant that p entails p v q. So *Trump won* entails that *Trump won or Ed lives in London.* But surely if I assert that Trump won, I do not assert that Trump won or Ed lives in London.

And of course the disjunct q could be any monstrous conjunction or disjunction of propositions.

Assertion is a speech act governed by various constraints. One is the Explicitness Condition: When I utter a sentence s to make an assertion, the content of the assertion is exactly the proposition explicitly expressed by s, and not any of its entailments (other than itself, of course.)

So if Sam asserts a self-refuting proposition, he asserts only that proposition, not its negation. If Sam asserts that nothing is true, he asserts precisely that, despite the fact that the content asserted entails that something is true.

[John Doran]

Late to the party, but:

I would reject your (1).

To ASSERT P just means to say, "this is true: P". I don't know what else it could mean.

If you maintain that it's possible to assert a proposition without intending to communicate your belief in the truth of that proposition, then I fail to see how that's any different from saying that the sound "bluuuurrrgh" coming out of my mouth is an assertion; or that my singing along with a song is an assertion of the lyrics; or the sound "god does not exist" coming from my parrot, is an assertion. or...

Assertions are illocutionary, or, perhaps less tendentiously, speech acts intended to communicate the truth of the utterance of the speaker to his interlocutor.

[The Bad Ostrich]

OK then, you win on (3).

So what about (4). Why does it follow that Sam does not ASSERT that there is at least one truth?

If p entails q, it may not follow that S asserts q. But it may still be true that S asserts q. You haven't shown otherwise.

Moreover, if p = p' & q, I claim that one who asserts p also asserts q (and p' to boot).

[BV]

>>If p entails q, it may not follow that S asserts q. But it may still be true that S asserts q. You haven't shown otherwise.<<

That's a good point. It occurred to me yesterday and I started to write a post about it, but didn't finish it.

*Tony won the race* entails *Tony competed in the race.* If I assert that Tony won the race, do I assert or do I presuppose that Tony competed in the race? I want to say that I presuppose that he competed in it. But I am not sure I can refute you if you insist I assert both that he won and that he competed.

I take it you are saying that in this example the content of my assertion is a conjunctive proposition: *Tony won the race & Tony competed in it* But then Frege's argument kicks in. The negation of the above conjunction is: *Tony did not win the race v Tony did not compete in it.*

But if I assert that Tony did not win the race, I am not asserting the disjunction just mentioned. If I am asserting two propositions, I am asserting the conjunction: *Tony did not win the race and Tony DID compete in it*

The proposition that survives negation -- *Tony competed in the race* -- is therefore a presupposition and not part of what is asserted.

In the case of Sam it seems intuitively obvious that this benighted sophomore has every intention of asserting that there are no truths, just that, and nothing else. Of course he doesn't see that the proposition entails its own negation. But from this ignorance on his part it does not follow that he is asserting a contradictory pair of propositions.

[BV]

I seem to be assuming that the speech act of assertion is such that one who asserts asserts all and only what he intends to assert . . .

[BV]

John Doran,

I hope you are not saying that 'S asserts that p' has the same meaning as 'it is true that p.' It can be true that p whether or not S asserts it, and that presumably holds for any S.

But we will agree that if I assert that p, then I intend to communicate my belief that p is true. Whatever one asserts one asserts to be true. Of course it doesn't follow that whatever one asserts to be true IS true.

But this obvious point leaves (1) standing. Sam intends to communicate to his interlocutor his belief that there are no truths, a belief that Sam thinks is true. He does not see that the content of his assertion entails its own negation. But that is irrelevant. So (1) stands.