shminux comments on Request for Steelman: Non-correspondence concepts of truth - Less Wrong

13 Post author: PeerGynt 24 March 2015 03:11AM

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Comment author: shminux 24 March 2015 05:20:51AM 6 points [-]

I went down the rabbit hole of researching the question "what is truth?" soon after I joined LW almost 3 years ago, and ended up with a rather unpopular anti-Platonic ontology of the term "truth" being worse than useless in most cases. The correspondence theory of truth stopped making sense to me because there is nothing for it to correspond to. So, it's somewhat more radical than William James's pragmatic theory of truth. But I guess this is probably not what you are interested in.

Comment author: seer 24 March 2015 07:15:54AM 10 points [-]

The correspondence theory of truth stopped making sense to me because there is nothing for it to correspond to.

It corresponds to reality.

As for what reality is, I like Philip K. Dick's formulation: "Reality is that which, when you stop believing in it, doesn't go away."

Comment author: shminux 24 March 2015 03:11:08PM 1 point [-]

Right, it's the last assumption that I ended up rejecting. But I've talked enough about it on this forum. And no, whatever straw interpretation of what I said that immediately comes to your mind, I don't mean that.

Comment author: [deleted] 24 March 2015 05:01:27PM 0 points [-]

ok what about the example from "the simple truth" -- jumping off a cliff. Is it not the case that you will fall to your doom regardless of your beliefs? can it not be said that the truth is that all things fall towards the earth and that does correspond to reality?

Comment author: shminux 24 March 2015 05:17:07PM *  0 points [-]

The Simple Truth shows that bad models are bad. It is not an argument for or against a specific concept of truth, despite what Eliezer might have intended by it.

Comment author: [deleted] 24 March 2015 06:11:47PM *  1 point [-]

What makes a bad model "bad", other than that it does not correspond to reality?

Comment author: shminux 24 March 2015 07:07:15PM *  0 points [-]

The predictions it makes are incorrect.

Comment author: [deleted] 24 March 2015 11:01:09PM *  0 points [-]

Ok I suspect we are using different definitions of 'correspond'. 'Correspond' means "a close similarity; match or agree almost exactly." In this context I have always interpreted 'correspond to reality' when applied to a model as meaning that models predictions have a close similarity; match or agree almost exactly with observation. That is to say, a model which corresponds to reality correctly predicts reality, by definition.

If my model says the sky should be blue, and I go out and look and the sky is blue, my model corresponds to reality. If my theory says the sky should be green, and I go out and look and discover the sky to be blue, then my model does not correspond to reality. It seems to me that a model which corresponds to reality and yet is incorrect (does not match the world) is a logical impossibility.

Therefore, I presume you must be using some other definition of 'correspond'. What might that be?

Comment author: shminux 24 March 2015 11:51:45PM 2 points [-]

Your wording:

If my model says the sky should be blue, and I go out and look and the sky is blue, my model corresponds to reality.

My wording:

If my model says the sky should be blue, and I go out and look and the sky is blue, my model is accurate/useful, etc.

I.e. I make no claims about reality beyond it occasionally being a useful metamodel.

It seems to me that a model which corresponds to reality and yet is incorrect (does not match the world) is a logical impossibility.

In the dualist reality+models ontology, yes. If you don't make any ontological assumptions about anything 'existing" beyond models, the above statement is not impossible, it is meaningless, as it uses undefined terms.

Comment author: [deleted] 25 March 2015 12:12:23AM 2 points [-]

Is there any actionable difference between the two viewpoints?

Comment author: buybuydandavis 25 March 2015 03:57:53AM 1 point [-]

I.e. I make no claims about reality beyond it occasionally being a useful metamodel.

It's really about the accuracy of your model in terms of predictions it makes, whether or not we can find any correspondence between those hidden variables and other observables?

Is that what you're getting at?

Comment author: TheAncientGeek 31 March 2015 09:18:10PM *  1 point [-]

If my model says the sky should be blue, and I go out and look and the sky is blue, my model corresponds to reality.

It corresponds to appearance. Models posit causal mechanisms, and the wrong mechanism can predict the right observations.

In general, the correspondence theory of truth means that a proposition is true when reality, or some chunk of reality,  is the way the proposition says it is. Translating that as directly as possible into physical science, a science, a theory would be true if it's posits, the things it claims exist, actually exist. For instance, the phlogiston theory is true if something with the properties of phlogiston  exists. The important thing is that correspondence in that sense, let's say "correspondence of ontological content", is not the same as predictive accuracy. To be sure, a theory would that is not empirically predictive is rejected as being ontological inaccurate as well.....but that does not mean empirical predictiveness is a sufficient criterion of ontological accuracy...we cannot say that a theory tells it like it is, just because it allows us to predict observations.

For one thing, instrumentalists and others who interpret science non realistically, still agree that theories are rendered true other false by evidence,

Another way of making this point is that basically wrong theories can be very accurate. For instance, the Ptolemaic system can be made as accurate as you want for  generating predictions, by adding extra epicycles ... although it is false, in the sense of lacking ontological accuracy, since epicycles don't exist.

Another way, still, is to notice that theories with different ontologies can make equivalent predictions, like wave  particle duality in physics.

The fourth way is based on sceptical hypotheses, such as Brain in a Vat and the Matrix. Sceptical hypotheses can be rejected, for instance by appeals to Occams Razor, but they cannot be refuted empirically, since any piece of empirical evidence is subject to sceptical interpretation. Occams's Razor is not empirical

Science conceives of perception as based in causation, and causation as being comprised of chains of causes and effects, with only the ultimate effect, the sensation evoked in the observer, being directly accessible to the observer. The cause of the sensation, the other end of the causal chain, the thing observed, has to be inferred from the sensation, the ultimate effect -- and it cannot be inferred uniquely, since, in general, more than one cause can produce the same effect. All illusions, from holograms to stage conjuring, work by producing the effect, the percept, in an unexpected way.  A BIV or Matrix observer would assume that the precept of a horse is caused by a horse, but it would actually by a mad scientist pressing buttons.

A BIV or Matrix observer could come up with science that works, that is useful, for many purposes, so long as their virtual reality had some stable rules. They could infer that dropping an (apparent) brick onto their (apparent) foot would cause  pain, and so on. It would be like the player of a computer game being skilled in the game. But the workability of their science is limited to relating apparent causes to apparent effects, not to grounding causes and effects in ultimate reality.

Comment author: Lumifer 24 March 2015 06:30:01PM 0 points [-]

For example, uselessness.

Comment author: [deleted] 24 March 2015 06:39:31PM 1 point [-]

Please forgive my continuation of the Socratic method, but what in what ways can a model be useless that differ from it not corresponding to reality?

Comment author: TheAncientGeek 27 March 2015 02:47:50PM 1 point [-]

A model can be useful without corresponding, though,

The Ptolemaic system can be made as accurate as you want for generating predictions.

Comment author: Lumifer 24 March 2015 06:44:18PM 1 point [-]

Recall an old joke:

A man flying in a hot air balloon realizes he is lost. He reduces his altitude and spots a man in a field down below. He lowers the balloon further and shouts, "Excuse me, can you tell me where I am?" The man below says, "Yes, you're in a hot air balloon, about 30 feet above this field." "You must be an mathematician," says the balloonist. "I am. How did you know?" "Everything you told me is technically correct, but it's of no use to anyone."

Comment author: gjm 24 March 2015 10:20:05PM 3 points [-]

"Very clever! And you must be a manager," says the guy in the field. "Amazing! How did you work it out?" asks the balloonist. "Well, there you are in your elevated position generating hot air, you have no idea where you are or what you're doing, but somehow you've decided it's my problem."

Comment author: GMHowe 25 March 2015 09:13:38PM 1 point [-]

It's a funny joke but beside the point. Knowing that he is in a balloon about 30 feet above a field is actually very useful. It's just useless to tell him what he clearly already knows.

Comment author: [deleted] 24 March 2015 11:09:46PM 0 points [-]

Sorry I'm dense. What does this have to do with anything? It is true that the balloonist is in a hot air balloon 30 feet above a field. These are correct facts. Are you arguing for a concept of truth which would not qualify "Yes, you're in a hot air balloon, about 30 feet above this field" to be a true statement?

Comment author: JohnBuridan 24 March 2015 05:48:20AM 1 point [-]

Do you really believe the word truth should be stricken? In a deep discussion, of course, the word doesn't really get used since you should be arguing about either facts, methods, or concepts.

I don't think the focus of this discussion is not quid est veritas? but a more pressing social question, "How can we have a discussion about truths, when we disagree about what makes a proposition true?"

Could you explain the pragmatic theory of truth a bit for the community?

P.S. I used to think that certain words were useless, until I decided/realized (through Wittgenstein) that I don't get to decide such things (plus I am completely terrified that my English usage is insulated or inarticulate, so I try to use ordinary language as much as possible).

Comment author: Jack_LaSota 30 March 2015 12:22:24PM -1 points [-]

"There is nothing for the correspondence theory of truth to correspond to" is a feature, not a bug. Because this is one of those philosophical debates which is really just a choice of definition. "Something is true if it corresponds to reality" is just a definition, and definitions don't have truth* value.

*truth defined in a way that I think is pretty useful to define it, which is what we're usually looking for when we pick definitions.