# How different would mathematics and science be if we'd assume truth does not exist?

This comes from the question "Is human intuition consistent with current structure of mathematics?" I asked myself.

Intuitively we agree on very many things and it seems we can "prove" almost everything. My example of that:

When someone says "It is cloudy" and you see clouds you agree with that. In fact you might even think the world is an illusion and clouds, your eyes, light emitted to your eyes, your eyes themselves, your brain and brain signals are illusions and so on. But you still agree that it's cloudy. So why?

In very deed I reject the notions of good, bad, right, wrong, true and false themselves. What I only accept is the sense. Different propositions, ideas, forms and actions might make more or less sense. Thus, when we agree on something we just mean what we think and say makes sense.

I think it is utterly difficult to define our intuition formally. It makes sense to say that our intuition is too complex to be described just by symbols. This led me to the thought that sensualistic logic is far more expressive than anything other we could think of.

Example of sense in mathematical meaning:

There were times when equation x^2=-1 was thought not to have solutions. So, no solutions exist meant "true". But now we say it is false. How can it be both true and false. The thing is that both "do not exist" and "exist" can be true. If you want to escape such ambiguity, you probably need to ask infinitely long question. But whrn we say about sense, we don't need to do it. Maybe we somehow can understand the context (which must be infinitely long to escape ambiguity) and give an answer according to it.

But mathematics are built on the notions of truth and false. Eventually that resulted in Gödel's theorems, Post's theorem an so on. These theorems state that nothing can be proved to be true. And still we agree on things, we think some of them make sense.

Another issue with mathematical foundations is that we try to define them formally. And my logic rejects the concept of formality. Is that an issue for mathematics?

It seems all this mean mathematics in its current form can't describe our way of thoughts. And assuming materialism that would be equal to say that mathematics in it's current form can't describe reality and define Theory of Everything. And if it's so, we need to change foundations of mathematics to advance further in physics.

But I'm wondering if my solution itself negates mathematics in it's current form, because without defining the truth we can't prove Gödel's theorems as they would involve undefined concepts. Actually, I even thought about self-referential propositions in my logic.

The proposition "This proposition does not make sense" indeed does not and the proposition "This proposition makes sense" does. So, self-referential paradoxes do not exist in sensualism.

But how deep are the differences between my logic and current logic of mathematics? Could we even define arithmetics using such logic? More interestingly, assuming my logic, would all the Millennium Problems retain their sense? And if no, then do Millennium Problems have sense right now?

What would be the consequences for science under this logic? Could that help us to advance further in science?

Logic described here must not be confused with intuitionistic logic or paraconsistent logic.

Examples of my logic:

1. A makes sense. Not A makes sense. Therefore, A and not A makes sense. A or not A makes sense as well.

2. A does not make sense. Not A does not make sense. Therefore, A or not A does not make sense. A and not A does not make sense as well.

3. A makes sense. Not A does not make sense. Therefore, A and not A does not make sense. Contrariwise A or not A makes sense.

In the case of several variables these rules might not work. Consider "Sun is large or bright". Actually, it does not make sense because it tries to find connection between the two, but there is none. But if we put 'and' instead of 'or', the proposition becomes meaningful, as 'and' may be used to link different properties.

Thus I assume such logic rejects negation in it's standard form, but does not reject the idea of negation.

• Just a comment on the final point, some would be inclined to interpret any binary expression containing at least one part which fails to make sense as making the entire formula fail to make sense. Take for example "either it is raining today or aiinfjnwefnrf". With truth, the value of a disjunction can obtain as true merely from a single value, but some may take "making sense" to be a property determined by entire formulae, and so cannot obtain when at least one of its parts fails to make sense. This is, at least, some pushback I would anticipate, in such a claim. – BeingOfNothingness Apr 27 '18 at 9:46
• Some clarification: 1) Are you sure Godel's theorems state that nothing can be proven true? It is certainly the case that some things cannot be proven, but not all things cannot be proven, given we follow the axiomatic foundations of a given system. 2) What do you mean: "It seems all this mean mathematics in its current form can't describe our way of thoughts." ? 3) And also, what do you mean here: "And assuming materialism that would be equal to say that mathematics in it's current form can't describe reality and define Theory of Everything." – BeingOfNothingness Apr 27 '18 at 9:52
• 4) Your title asks about truth "not existing", although I'm unsure what you mean by that. Whereas, in the text, you talk about leaving truth undefined (although Tarski's undefinability theorem would say there is no problem with this and that we should do this anyway). – BeingOfNothingness Apr 27 '18 at 9:53
• @BeingOfNothingness, 1) Can not be proven within current mathematics. Of course, all those theorems are just the result of current foundations of mathematics. 2) We somehow decide what makes sense and what does not but we can not say how and why we do it. 3) If we assume these capabilities arise from inner properties of universe, we need to say everything in universe has potential capability for that. 4) I think mathematics uses some kind of "existense" notion. – rus9384 Apr 27 '18 at 10:12
• It seems to me that many mathematicians and scientists doubt the possibility of truth but it makes no difference to their work. Truth is not an issue in these fields, only truth-values within the system that are relative to other relative truths. . . . – user20253 Apr 27 '18 at 13:40

"Is human intuition consistent with current structure of mathematics?" I asked myself.

You asked a wrong question that is, interestingly, just in the opposite direction. Mathematics is built upon definitions. So I can define anything I want (even if it may be counter-intuitive to you) as long as my system/structure is consistent. To me, it is the mathematical structure to go with human intuition, not the converse. That is

One can change a part of the definitions of current math to "create" "new" math, in your case to fit human intuition, as long as it's still consistent. (don't put much effort on those weird words I used here.)

First, "intuitive" is subjective. And a useful mathematical structure is not necessarily "human intuitive", could you please elaborate more on this part? Why do you need a structure to be human intuitive? When one is unclear about an idea then the idea is not intuitive to him but after a while it may become intuitive because he learn it.

On the other hand, in my own opinion you should ask

Is the current structure of mathematics consistent with human intuition?

I won't give you an answer to this because please define human intuition. (A mathematical fact may be intuitive to someone but not the case for others)

What I've learned from math is that when you don't know what you're talking about, that is, the words you're using are ambiguous/vague, don't ask question. Now let's move on to your questions

[...] you might even think the world is an illusion [...] But you still agree that it's cloudy. So why?

You can think the world is an illusion, but so what? What he's asking is that whether you see "it's cloudy", and yes you could say it's "illusionally cloudy" but this is just a subset of "cloudy".

[...] What I only accept is the sense. Different propositions, ideas, forms and actions might make more or less sense. Thus, when we agree on something we just mean what we think and say makes sense.

So what do you mean "make sense"? What your words are conveying is that "so we have wars". A thing makes sense to you may not to others, but interestingly you said

["]In very deed I reject the notions of good, bad, right, wrong, true and false themselves.["]

That's a part of the reason of wars, because "I do whatever make sense to myself and don't even care that's good/bad/right/wrong/whatsoever to you".

["]But mathematics are built on ... Gödel's theorems.... These theorems state that nothing can be proved to be true.["]

No, I'm very sure that you're unclear about Gödel's theorem. The theorem says there are something cannot be proved to be true, which is not equivalent to "nothing can be proved to be true". Be careful when you're make a conclusion about a thing you're not completely clear about. If you really want to get a whole picture about this theorem take 10 mins to watch Gödel's Incompleteness Theorem - Numberphile.

["]It seems all this mean mathematics in its current form can't describe our way of thoughts.["]

Yes, it can. The purpose of logics, which is a part of mathematics to me, is to describe our way of thought. When you was composing your question you took the advantage of logics so we can make deduction from your words.

Forgive me to skip the latter part of your question because my answer is quite long now. I won't say it's a bad question and I won't touch the vote but I wondering why it didn't attract downvotes because you made a lot of assumptions that math was wrong and the earth is still rotating.

• I meant why human intuition is so strong: we can understand notions without definitions (basis of language). And, well, I know we can evaluate something to 'true', like Presburger arithmetic. But the problem then is if there even a sense of defining something that can't be true? – rus9384 May 2 '18 at 7:53
• "But the problem then is if there even a sense of defining something that can't be true?" what we know about math is that it should be consistent, but be consistent doesn't mean it have to match the "reality"(I assume that your "can't be true" means it doesn't fit the "reality", whatever this word means.). But how do you know it won't fit our reality in the future? Maybe one day we will find it useful. Irrational number was considered useless in ancient days, but then? Anyway, that's a good point. – user25207 May 2 '18 at 8:02
• @user25207. +1. I don't think maths or science could operate without some notion of truth. E.g., the idea of consistency built into both assumes that the truth one proposition excludes the truth of another. The truth assumed could belong to a conventionalist theory but I don't see how all idea of truth can be eliminated. Best : GT – Geoffrey Thomas Jun 2 '18 at 9:29