Actually the nature of truth is an unresolved and debated question.
There are reasons to discount the concept of absolute truth.
Take your example:
I happen to wear black socks at the time of this writing. Believe it or not, that’s the reality, so “Loup was wearing blacks socks when he wrote this” is true for everyone, including you. Even if you believe I’m lying, I am wearing black socks. You can’t be absolutely certain of this fact, but a fact it is.
Your statement is true as assessed from a certain context; if assessed from other contexts it might be false. For example, under a different light source your socks may appear to blue due to illuminant metameric failure, or may even glow due to phosphorescence.
Truth can only be determined from the context of assessment.
For those that disagree I’ll take your down-votes, but please also comment, pointing me to references if possible; I’m actively researching this aspect of epistemology.
By non-universality of truth you mean that there is no function from the set of propositions formulated in a natural language to {0,1} which fulfills the expectation we have from truth? That’s true (ehm...) , but the reason is rather trivial: words of natural languages don’t specify the meaning uniquely and some amount of interpretation is always needed to figure out the meaning of a proposition. Given that propositions can probably be formulated with arbitrary precision if needed (even if not infinitely so), the disputes about meaning can be always resolved.
...words of natural languages don’t specify the meaning uniquely and some amount of interpretation is always needed to figure out the meaning of a proposition.
The need for interpretation is not limited to natural languages; it is required for any language. A context of assessment will derive meaning from a proposition based on its prior assumptions. For example a raw bit string may be interpreted to different meanings when read by different programs.
Given that propositions can probably be formulated with arbitrary precision if needed (even if not infinitely so), the disputes about meaning can be always resolved.
To resolve such disputes there must be a computable path to the resolution, and there won’t always be such a path. At a fundamental level not all problems are decidable. In more practical terms, the contexts involved in the dispute must implement some system that allows for convergence for all possible inputs; this condition will not always be satisfied.
I’m not claiming that there is no truth, or that belief alters reality; I’m claiming that truth can only be determined within the context of assessment; that there is no absolute or objective truth.
I realize that this is at odds with some of Eliezer’s claims. But to provide an example related to Eliezer’s belief in mathematical realism. (Why isn’t this an obvious mind projection fallacy?)
Let’s say Fred performs a calculation that results in 2 + 3 = 6. This isn’t just a onetime mistake, he always calculates 2 + 3 as 6; if he sees the formula written down he will say, “Hey, that’s true.”
Why is this clearly false statement true to Fred? It’s because his mental implementation of the arithmetic abstraction is broken… from our perspective. Just because he believes that 2 + 3 = 6, it doesn’t mean that it’s true in any other context of assessment.
Just because we believe that 2 + 3 = 5, that doesn’t mean that the statement is an absolute truth. We can only evaluate the truth of the statement by assessing it within contexts that can give the statement meaning. My mailbox doesn’t do math at all, but my calculator does a fair job; although for my calculator I have to first transform the symbols into key presses.
Edited to add:
In the story you reference, the character Mark presumably dies when he jumps off a cliff believing that his beliefs would allow him to fly. Our minds are not a context of assessment for physical stuff, like our bodies or the ground; we can observe stuff by forming meaning from our senses, but we don’t provide the framework that gives that stuff its existence and that allows it to interact. We are subject to the context of assessment that generates our physical reality.
Actually the nature of truth is an unresolved and debated question.
There are reasons to discount the concept of absolute truth.
Take your example:
Your statement is true as assessed from a certain context; if assessed from other contexts it might be false. For example, under a different light source your socks may appear to blue due to illuminant metameric failure, or may even glow due to phosphorescence.
Truth can only be determined from the context of assessment.
For those that disagree I’ll take your down-votes, but please also comment, pointing me to references if possible; I’m actively researching this aspect of epistemology.
By non-universality of truth you mean that there is no function from the set of propositions formulated in a natural language to {0,1} which fulfills the expectation we have from truth? That’s true (ehm...) , but the reason is rather trivial: words of natural languages don’t specify the meaning uniquely and some amount of interpretation is always needed to figure out the meaning of a proposition. Given that propositions can probably be formulated with arbitrary precision if needed (even if not infinitely so), the disputes about meaning can be always resolved.
The need for interpretation is not limited to natural languages; it is required for any language. A context of assessment will derive meaning from a proposition based on its prior assumptions. For example a raw bit string may be interpreted to different meanings when read by different programs.
To resolve such disputes there must be a computable path to the resolution, and there won’t always be such a path. At a fundamental level not all problems are decidable. In more practical terms, the contexts involved in the dispute must implement some system that allows for convergence for all possible inputs; this condition will not always be satisfied.
http://yudkowsky.net/rational/the-simple-truth
I’m not claiming that there is no truth, or that belief alters reality; I’m claiming that truth can only be determined within the context of assessment; that there is no absolute or objective truth.
I realize that this is at odds with some of Eliezer’s claims. But to provide an example related to Eliezer’s belief in mathematical realism. (Why isn’t this an obvious mind projection fallacy?)
Let’s say Fred performs a calculation that results in 2 + 3 = 6. This isn’t just a onetime mistake, he always calculates 2 + 3 as 6; if he sees the formula written down he will say, “Hey, that’s true.”
Why is this clearly false statement true to Fred? It’s because his mental implementation of the arithmetic abstraction is broken… from our perspective. Just because he believes that 2 + 3 = 6, it doesn’t mean that it’s true in any other context of assessment.
Just because we believe that 2 + 3 = 5, that doesn’t mean that the statement is an absolute truth. We can only evaluate the truth of the statement by assessing it within contexts that can give the statement meaning. My mailbox doesn’t do math at all, but my calculator does a fair job; although for my calculator I have to first transform the symbols into key presses.
Edited to add:
In the story you reference, the character Mark presumably dies when he jumps off a cliff believing that his beliefs would allow him to fly. Our minds are not a context of assessment for physical stuff, like our bodies or the ground; we can observe stuff by forming meaning from our senses, but we don’t provide the framework that gives that stuff its existence and that allows it to interact. We are subject to the context of assessment that generates our physical reality.