Tuesday, October 26, 2021

Can one lie without asserting a proposition?

I am starting to think that one can lie without asserting a proposition.

Let’s say that a counterintelligence agent tells an enemy spy that a new weapons technology has just been deployed, in order to dissuade the enemy from invading. The description of the technology contains nonsensical technobabble. This seems to be a lie. If it is, my argument is complete, because nonsense does not express a proposition.

But suppose we say it’s mere BS. Let’s now complicate the case. The counterintelligence agent passes to the enemy spy a fake classified document saying “We have just built a weapon that shoots three simultaneous hyperquark beams.” The spy is taken in by the BS, but also wishes to deter war. And thus the spy reports to her government: “The enemy has just built a weapon that shoots ten simultaneous hyperquark beams.” It is clear that the spy is not merely engaging in BS. The spy sure seems to be lying. But the spy is no more asserting a proposition than the counterintelligence agent did.

If we say that the counterintelligence agent is lying, then we have to allow that one can lie without even taking oneself to assert a proposition.

If we think that the counterintelligence agent is only BSing, but that in my more complicated case the enemy spy is lying to her government, then we should say that to lie one needs to take oneself to be asserting a false proposition, but one need not be actually asserting a proposition, true or false.

In either case, one can lie without asserting a proposition.

Perhaps I am wrong. Perhaps what the spy does in the more complicated case is neither BS nor a lie, but engaging in a verbal deceit we don’t have a good name for.


Walter Van den Acker said...


If I tell you that 1+1 is 3,is hat a proposition or not?

Alexander R Pruss said...

Yes, that's false, so it's a proposition.

Walter Van den Acker said...

But, 'We have huilt a weapon that shoots jhyperquark beams' is also fzlse.
So, how is that different?
You light say that hyperquark beeld are nonsense, but 1+1 is 3 is also nondense.
If I tell you that I have made a square circle, that too seems like a proposition toe me,because it is definitely false that I made such a thing.

SMatthewStolte said...

What if we use Escher sentences instead? Suppose I hear my friend Smith say, “A lot more people have been to Russia than I have,” and I don’t quite know what this means, but I am worried it might scuttle his chances for a promotion in the intelligence community. So I go to Smith’s boss and say, “Not many more people have been to Russia than Smith has, I’ll tell you that!” thinking that I have said something meaningful and false and also thinking (rather foolishly) that I have somehow helped Smith’s career prospects.

I might grant that the sentence “We have just built a weapon that shoots three simultaneous hyperquark beams” asserts a proposition, even if ‘hyperquark beams’ is a made-up and under-defined term. But I’m confident that Escher sentences don’t.

SMatthewStolte said...

I’ve argued (in private conversations) that it is possible to have a degree of belief in sentences that aren’t meaningful, so long as one takes them to be meaningful and has some basic guesses about what kind of implications they might have. In this case, I guessed that Smith’s sentence implied lower qualifications for the promotion.

Alexander R Pruss said...


1+1=3 isn't nonsense. What it says depends a bit on foundations of math questions, but roughly it says that when you apply the addition function to the pair (1,1), the result is 3. You understand what this means, and that's why you can see that it is false.

In the case of "We have huilt a weapon that shoots hyperquark beams", you don't know what it means. And when you deny it, you don't know what you are denying.


Yes, I agree that these Escher sentences make for an even better case, but I've never heard of them before.

On reflection, I am now thinking that a reasonable response both to my second example and to your example is that one is not lying, but one is engaging in something like a failed attempted lie (though there are complications that I'm about to blog on). However, one may be lucky enough that the failed attempted lie succeeds at its deceptive end if the audience is sufficiently clueless.

Alexander R Pruss said...

Actually, no need to blog on the complications. I've already done it (but in a different case than lying): https://alexanderpruss.blogspot.com/2016/08/attempted-murder-is-not-attempt-to.html