Tuesday, October 17, 2017

Approximate truth and the very recent past

Suppose I say that Jim yelled in delight at 12:31. But in fact he did so at 12:32. Then I said something false but approximately true.

Now, suppose that I hear Jim giving a loud yell of delight about 300 meters away. While I am listening to that yell, I think that Jim is yelling. But in the last second of my hearing, Jim is no longer yelling, but the sound waves are still traveling to me. No big deal. My belief that Jim is yelling is false, but approximately true. Or so I want to say.

And it’s important to say something like this, for it allows us to preserve the idea that our sense give us approximate truth. The case of sound from 300 meters away is particularly strong, but the point goes through in all our sensation, as none of it travels faster than the speed of light. Now, granted, often when we become aware of a stimulus, our sensory organs are still undergoing it. But nonetheless it is strictly speaking false to say that this very part of the stimulus that we are now aware of is in fact going on. So our senses seem to lead us slightly astray. But at most very slightly. It is approximately true that this part of the stimulus is going on now, because it is in fact going on a fraction of a second earlier. Or, perhaps, it is a part of our common sense knowledge of the world that the data of the senses is only meant as an approximation to the truth, and so there is no straying at all.

Now imagine that I say that Jim actually yelled in delight at 12:31, but he was actually completely silent all day, although in a very nearby possible world he did yell in delight at 12:31. Then what I said is not approximately true. In ordinary contexts, the modal difference between the actual and the merely possible vitiates approximate truth, no matter how nearby the merely possible world is.

So now on to one of my hobby horses: presentism. If presentism is true, then the difference between what is happening now and what happened earlier is relevantly like the difference between the actual and the possible. In both cases, it is a difference between a neat and clean predication and a predication in the scope of a modal operator, pastly or possibly, respectively. If this is right, then if presentism is true, I cannot say what I said about its being approximately true that Jim is yelling if Jim has actually stopped. That difference is a very deep modal difference. That the time when Jim is yelling is in a nearby past no more suffices for the approximate truth of “Jim is yelling now” than that Jim is yelling in a nearby possible world is enough for the approximate truth of “Jim is actually yelling”. The ontological gulf between the actual and the possible is vast; so would be the ontological gulf between the present and the past if presentism were true.

Thus, the presentist cannot say that the senses tend to deliver approximate truth.

Objection: We know to correct the data of the senses for the delay.

Response: We know. But that's a recent development.


Christopher Michael said...

I don't find this argument convincing in part because I don't see why we should say, even for the presentist, that tenses are modalities. It seems to me that the presentist can give all the same reasons for approximate truth that the eternalist gives. It might help to know what you think modality is, exactly, and why tenses are modalities if presentism is true. Another part of why I don't find this argument convincing is my being a presentist. :-)

But more importantly, shouldn't the Aristotelian presentist expect the past and the future to be relevantly like the possible? After all, the merely possible becomes actual through the very same process by which the future becomes present and the present past: change, which is just the actualization of potentialities, which are just first-order mere possibilities. Given that the same process governs both systems, we have some reason to expect them to have metaphysically similar structures.

Alexander R Pruss said...

Well, the "pastly" operator behaves like a modal operator. And one cannot pull out existential import from the its scope, if presentism is true, just as one cannot do so from possibility operators. Moreover, "pastly, p" makes p not describe how things really are, just as "possibly, p".

Alexander R Pruss said...

Isn't the gulf between being and nonbeing immense?

Michael Gonzalez said...

Is it not common-sensically obvious (at least, to the lay, uninitiated person) that the past is an integral part of the present? No one thinks that a ball showing up in my hand out of nothing (or, out of mere potentiality) is anything like the ball showing up in my hand because my brother threw it at me. The present is suffused with and defined by its origins in a way that the actual is certainly not suffused with alternate possibilities. Or, rather, if you choose to think of actuality as suffused with the alternate possibilities (in that each actual event is tinted and contextually defined by what could have been), then the two cases are alike, but the "gulf" is gone.

In any case, to the presentist (and the layman), there is no mere arriving of sound at my ears. There is the arriving of the sound from Jim's yell at my ears. That is a relevantly different event.

So, the point is not the gulf between being and nonbeing. The point is that what currently has being is a past-produced and past-suffused present. This ball has trajectory because it was thrown. Etc.

Alexander R Pruss said...

No, there is still a gulf. The difference between potentiality and its actualization is immense. They are correlated, but also opposed.

Christopher Michael said...

Potentiality is not nonbeing. This is a crucial distinction. If potentiality were nonbeing, Aristotelian hylomorphism would be no better off than Heracliteanism. Part of what we found out when we found out that Aristotelian hylomorphism is true is that being is divided between actuality and potentiality. Potentiality is a kind of being.

And no, it's not clear at all that there is a gulf between actuality and potentiality. There is a distinction, for sure, but countless potentialities are within ontological arm's reach. Potentiality comes right up to and kisses actuality; there is no gulf between them, only a distinction. We even psychologically experience how close some potentialities are to actuality as dramatic tension, fear, or anticipation.

Alexander R Pruss said...

The potentiality for F is nothing like F. But it is a form of being, but not of being F, not even approximately.

Michael Gonzalez said...

Consider this: The case where someone kills someone else, but could not have done otherwise (the latter clause being purely a matter of possibility; not actuality) is considered quite different from the case where he kills someone but could have done otherwise (again, a statement purely about possibility; not actuality). If possibility taints or colors the actual in such a palpable and (at least morally) relevant way, why couldn't the past have a similar presence (no pun intended) in the present? Why can't it be the case that "this sound that arrived from Jim's yell" is a categorically different sound from an otherwise identical one that came from a recording or some other source. Indeed, I think we intuitively know there is a difference. That's why I use the example of a baseball that has been passed to me. A passed ball is very different from a ball with identical trajectory that wasn't being passed to me.

Alexander R Pruss said...

Sure: a sound that arrived from Jim's yell is different from a sound that came from a different place. But both are very different from Jim's yell.

Maybe a part of the confusion is that I am tacitly assuming a naive realism about experience: The intentional object of perception is Jim's present yell, not "a sound that arrived from Jim's yell", nor a quale in the mind, etc.

Michael Gonzalez said...

On the contrary, I was trying to word things in a more commonly acceptable way. I would definitely have said "Jim's yell" is categorically different from some otherwise identical sound. And my point is simply that "the world as it is now" is not the right subject for consideration. It's "the world in the state it has arrived at via the particular path of history that led here". And, indeed, an otherwise identical world, arrived at through some different history, would be a different world even in the present moment (just as Jim's yell that I'm hearing is categorically different from any other identical sound). It matters how we got here, and the "here and now" is suffused with its origins.

For what it's worth, I don't think anyone would say "Jim is yelling" just because they hear his yell, if they can tell that he's quite far away. They would probably say "Jim yelled". "Jim is yelling" implies that he still intends to continue. He's got more to say.