Then who is watching you when you are asleep. Does that mean you don't exist when you are asleep. — Abhiram

According to Hume, idea of self doesn't exist. What did Berkeley say about SELF?
But the real question here was, how do you know the existence of the being which,

have existence in this physical world but all encompassing physical reality , space, time and thought with it. Like an intertwined whole with several distinguishable parts which cannot be separated — Abhiram

??

And, to tie it back to the OP, math is one of those things, restricted to human Consciousness and, therefore, only "real" insofar as constructed and perceived. — ENOAH

Agreed. Human consciousness applies math to all the objects in the universe, but some folks think that math is embedded in the universe.

I wish people into scholastic philosophy and theology were obliged to study Modern Greek so they realise how silly they sound, and how the usage of foreign words does not grant them mystique. — Lionino

Is Modern Greek a lot different from Ancient Greek? It would be advantageous to know Ancient Greek for reading philosophy.

In the logic thread I proposed "logos" for the logic-like function of the world. I wonder what a good term would be for "the apparently mathematical in nature?" Quantos? Mathematicularity? Máthēma? Quanticularity? — Count Timothy von Icarus

Are there anything more than matter and motion in the universe?

No. They're not that fancy. They're practicing math scholars and philosophers. — L'éléphant

gotcha.

Is Modern Greek a lot different from Ancient Greek? — Corvus

Attic Greek for Plato, Aristotle, etc? Yes. Hellenistic/Roman Greek for neo-Platonists and theologians? Not that much.

We use math to model the universe but all those models are open to further investigation, some of which is going on. For instance, the universe of Galileo was a three-dimensional Euclidean space. The universe of general relativity is a curvy space where even the curvature is changing all the time.

Both of those spaces use real numbers, but attempts to combine quantum mechanics and relativity have come up with alternatives, like a discrete space with very small but non-zero lumps of space time that cannot be subdivided. Another such attempt posits that the universe is on a curved 2-D space where information affects act mathematically to mimic the behavior of 3-D gravity inside the curve. Even our 3-D visual perception of the world is manufactured in the brain from 2-D input by specialized neural processes that have to be visually triggered in infancy. Evolution gave us a brain that presents a 3-D world to us because it is a good approximation that helps species' survival, not because it is real.

Some quantum theoretical interpretations posit that the universe is really google-dimensional, perhaps with even the number of dimensions changing, and 3-D space is a good approximation due to information effects.

Another alternative to real-valued dimensions comes from non-standard analysis - see (https://www.wikiwand.com/en/Nonstandard_analysis), which expands the reals to include infinitesimals, which are smaller than any real number but greater than zero, and their reciprocals, unbounded numbers, which are larger than any real but less than infinity = 1/0. See (https://www.researchgate.net/publication/330751668_Infinitesimal_and_Infinite_Numbers_as_an_Approach_to_Quantum_Mechanics).

Another QM interpretation holds that the quantum field is a Hilbert space, not just mathematically but actually, which would make the physical world part of the set-theory universe, reversing the question this thread raises. I personally find this non-appealing for a few reasons. One is that the 3-D Euclidean space of Galileo is also a Hilbert Space, but no one ever thought his universe was part of the set theory universe. Another is that you would then have to consider the reality of the set-theory universe, which would be an interesting thread in itself but is a lot to insert into physics.

In the end, how the universe is modeled mathematically is still up in the air. Inserting the mathematical universe into those physical models would not be very helpful.

Attic Greek for Plato, Aristotle, etc? Yes. Hellenistic/Roman Greek for neo-Platonists and theologians? Not that much. — Lionino

I recall reading somewhere, that in Platonic era of ancient Greece, there was no Greek word for "truth". Is this correct?

That is nonsense, the word for truth goes back to Homer.

I am not sure whether what I am about to write is on-topic but here goes.

Imagine that you are reduced down to being a "brain in a vat" but you also have eyes. Now imagine that you are floating in a universe that is devoid of all matter and all energy. Your only "experience" is that of complete and total darkness.

To me, this is a conceivable state of affairs and suggests that numbers are not independent of the real world - as a brain-in-a-vat, where would you "get" any concept of numbers? You have no fingers to count, nothing to touch or see that discloses "multiplicity": 2-ness, 3-ness. 4-ness and so on. By contrast, in the real world we actually live in, I suggest we get the concept of, for example, 3-ness, by seeing 3 apples, counting 3 fingers and so forth.

In summary, I suggest there are conceivable universes in which there is no reason to believe numbers exist as "things" in any sense at all, no matter how abstract - we need a real world that demonstrates 2-ness, 3-ness, 4-ness, etc. to stimulate us to create the concept of numbers.

That is nonsense, the word for truth goes back to Homer. — Lionino

The closest ancient Greek word for truth is "aletheia", which can be analysed etymologically a (negation) + lethe (concealment, forgetfulness, escape) = aletheia.
It doesn't quite reflect a word for truth, does it?

The closest ancient Greek word for truth is "aletheia", which can be analysed etymologically a (negation) + lethe (concealment, forgetfulness, escape) = aletheia.
It doesn't quite reflect a word for truth, does it? — Corvus

It does, because there is no such contrived meaning for alithia, it comes from alithis which means true. Truly in English means "really" all the time, does that mean English has no word for truth? "True" originally meant "in good faith".

Truly in English means "really" all the time, does that mean English has no word for truth? — Lionino

Truly can mean truthfully and rightly too. Truth is an English word for truth. :D
Anyway, "aletheia" is a Greek word for "truth", but it comes from the etymology "Not"+"Concealment" = a+lethia = alethia. I thought it was an interesting word. Would it imply that truth is hidden by nature?

On the contrary, the metaphor is that truth is not hidden. But they didn't make up this meaning, it likely shifted naturally with time — like 'true' did. There is no mystique to it. Take psefdomai, it means 'to lie', 'to be wrong'. How can there be no word in Ancient Greek for 'truth' if they have a word for 'lie'.

It was from an article called "Plato and Aristotle on Truth and Falsehood" by Jan Szaif, 2018 OUP.

He says due to the fact it is difficult to translate "aletheia" into the English word "truth". He also points out the word "aletheia" had been used by Heidegger to describe the character of the world.

He says due to the fact it is difficult to translate "aletheia" into the English word "truth" — Corvus

It is also difficult to translate "truly" into the Greek word "alithinos", for the reason I brought up above. It is also difficult to translate "demokratia" into the English word "democracy". Despite not having read the article, I don't think Jan Szaif's point is that Greek had no word for truth.

He also points out the word "aletheia" had been used by Heidegger to describe the character of the world. — Corvus

500 years from now I will come back from the dead and use the word "Heidegger" to describe break-dancing at a beach. Hopefully the academics will talk about that in 600 years.

Despite not having read the article, I don't think Jan Szaif's point is that Greek had no word for truth. — Lionino

I think his point is that aletheia in ancient Greek meaning is different from modern day meaning of truth.
I will read the article again when I am freer, and will try to update further.

500 years from now I will come back from the dead and use the word "Heidegger" to describe break-dancing at a beach. Hopefully the academics will talk about that in 600 years. — Lionino

Do you believe in eternal resurrection? That would be a Nietzschean idea, wouldn't it?

It is called existential experience. You know you exist ?right? It is simply the experience of your existence. You are experiencing it you can't deny it. It is simply that experience. If you are not aware of it then I suppose you might have to wait for an existential crisis to happen. Then you will be aware of your existence.

It is called existential experience. You know you exist ?right? It is simply the experience of your existence. You are experiencing it you can't deny it. It is simply that experience. If you are not aware of it then I suppose you might have to wait for an existential crisis to happen. Then you will be aware of your existence. — Abhiram

Initially when you were describing about the being, I thought you were talking about some other being than yourself. But from your post above, it appears that you must have been describing you yourself as a being encompassing

physical reality , space, time and thought with it. Like an intertwined whole with several distinguishable parts which cannot be separated — Abhiram

Is it correct?

It is also difficult to translate "truly" into the Greek word "alithinos", for the reason I brought up above. It is also difficult to translate "demokratia" into the English word "democracy". Despite not having read the article, I don't think Jan Szaif's point is that Greek had no word for truth. — Lionino

Truth in ancient Greek meant concrete existence opposed to mere appearance or beliefs. In Plato truth was not available in the material world, but truth belonged in the world of idea. Aristotle's truth was truth deducted from his syllogism. They had no idea of verified truth from observation and experiment.

Therefore even if they had a word aletheia which is closest meaning for todays word "truth", it wasn't identical meaning to today's concept of truth.

Truth in ancient Greek meant concrete existence opposed to mere appearance or beliefs — Corvus

First you said it means unconcealed, now this. Which one is it?

They had no idea of verified truth from observation and experiment. — Corvus

Really?

ταῦθ᾽ ὅτι ἀληθῆ λέγω
the truth of this story
Aeschin. 1 44

καὶ ἐπὶ τῆς γλώττης δὲ καὶ ἐπὶ τῶν μεταφορῶν καὶ ἐπὶ τῶν ἄλλων ἰδεῶν μετατιθεὶς ἄν τις τὰ κύρια ὀνόματα κατίδοι ὅτι ἀληθῆ λέγομεν
Take a rare word or metaphor or any of the others and substitute the ordinary word; the truth of our contention will then be obvious.
Aristot. Poet. 1458b

ὡς ὁ Ἱππίας ἀποστήσας ἀπὸ τῶν ὅπλων τοὺς πομπεύοντας, ἐφώρασε τοὺς τὰ ἐγχειρίδια ἔχοντας, οὐκ ἀληθής ἐστιν
but the current story that Hippias made the people in the procession fall out away from their arms and searched for those that retained their daggers is not true
Aristot. Const. Ath. 18

αὐτῷ διηγήσατο καὶ μάλα ἀξίους ἀκοῆς, εἶπέ τε ὅτι πᾶσα ἀνάγκη εἴη τοῦτον ἐλλόγιμον γενέσθαι, εἴπερ εἰς ἡλικίαν ἔλθοι.
Τερψσίων
καὶ ἀληθῆ γε, ὡς ἔοικεν, εἶπεν. ἀτὰρ τίνες ἦσαν οἱ λόγοι; ἔχοις ἂν διηγήσασθαι;
he had with him, which was well worth hearing, and he said he would surely become a notable man if he lived.
Terpsion
And he was right, apparently. But what was the talk? Could you relate it?
Plat. Theaet. 142d

οὐκ ἂν ἑτέρων ἔδει σοι μαρτύρων: οὕτω γὰρ ἄν σοι συνῄδεσαν ἀληθῆ λέγοντι
for then the truth of your statements would have been ascertained by the very persons who were to decide upon the matter.
Lys. 7 22

καὶ ἐπιεικῶς, ἦν δ᾽ ἐγώ, ἀληθῆ ἀπήγγελται.
Then the report, I replied, is pretty near the truth.
Plat. Charm. 153c

φέρε δὴ γνῶμεν, εἰ σὺ ἀληθῆ λέγεις, ποῦ καὶ χρήσιμοι ἡμῖν εἰσιν οἱ ὕπακροι οὗτοι;
Come now, let us make out, if what you say is true, where these second-best men are also useful to us
Plat. Lovers 136c

οὐκοῦν κοινὰ τά γε φίλων λέγεται, ὥστε τούτῳ γε οὐδὲν διοίσετον, εἴπερ ἀληθῆ περὶ τῆς φιλίας λέγετον.
And, you know, friends are said to have everything in common, so that here at least there will be no difference between you, if what you say of your friendship is true.
Plat. Lysis 207c

it wasn't identical meaning to today's concept of truth. — Corvus

What today's concept of truth? 'Veritè' also does not have the identical meaning of 'truth'.

Greeks did not have theories of truth like we have today, but many philosophers back then talked about what truth is. How can they not have a concept of truth? Greeks knew that "the sky is blue" is true and "the sky is green" is false. That "true" does not match "alithís" is a mootpoint, there is no such thing as a perfect translation, because every language imparts a worldview onto its speakers (the likelihood of two worldviews being identical is close to 0).

First you said it means unconcealed, now this. Which one is it? — Lionino

Unhidden and unconcealment was the Etymology, and concrete existence opposed to mere appearance or beliefs is Epistemology.

What today's concept of truth? — Lionino

Today's concept of truth is vastly broader with the modal logic, fuzzi logic and dynamic, epistemic logic ... etc etc and Science has many different concept of truth too.

Greeks knew that "the sky is blue" is true and "the sky is green" is false. — Lionino

The sky is blue is not always true. The sky is black at nights, and grey in cloudy days. The sky is green is true if you wore a green sunglass and look at the sky. Hence, the sky is blue is only true when the sky is blue. The sky is green is true when you wear a green colour lensed sunglasses and look at the sky, or through the green glass of the window.

That "true" does not match "alithís" is a mootpoint, — Lionino

That sentence is false.

Greeks did not have theories of truth like we have today, but many philosophers back then talked about what truth is. How can they not have a concept of truth? — Lionino

Talking about true things and truths doesn't verify that they had real concept of truth. It just means that they were expressing their psychological state or intention to indicate that they agreed to something, they feel something is right, or they have unconcealed something from the hidden.

I suggest you ask a Greek linguist instead of me.

they agreed to something, they feel something is right, or they have unconcealed something from the hidden. — Corvus

These seem like concepts of truth to me. Maybe they hadn't developed certain vocabularies about truth that modern philosophy has, but... if they agree with one statement about the world and disagree with another one, does that not imply at least a most basic concept of truth?

I suggest you ask a Greek linguist instead of me. — Lionino

I thought you could be a Greek, but don't appear so.

These seem like concepts of truth to me. Maybe they hadn't developed certain vocabularies about truth that modern philosophy has, but... if they agree with one statement about the world and disagree with another one, does that not imply at least a most basic concept of truth? — flannel jesus

The question had been raised due to the comment in Szaif's article. But I also believe that ancient Greek had concept of Truth. It was just Szaif's point that the ancient Greek's concept of truth was much different from modern concept of truth mainly due to the peculiarity of the Etymological origin of truth. I was wondering if that comment could be further elaborated and proved with some evidence by a native Greek folk.

I thought you could be a Greek, but don't appear so. — Corvus

I am not, but I know many Greeks. I think they would stand by that there is nothing different between Greek's and English's 'true', etymology nonwithstanding.

I am not, but I know many Greeks. I think they would stand by that there is nothing different between Greek's and English's 'true', etymology nonwithstanding. — Lionino

If truth is something that is unconcealed, that sounds like an implication for the existence of truth in the empirical world. Truths are hidden in the world, and you have to look for the truths, and disclose them from the hidden into your mind.

That view certainly contrasts the belief that truth is a product of perceptions and reasoning in human mind.

Another QM interpretation holds that the quantum field is a Hilbert space, not just mathematically but actually, which would make the physical world part of the set-theory universe, reversing the question this thread raises. I personally find this non-appealing for a few reasons. — Gary Venter

From ChatGPT 3.5:

Quantum field theory (QFT) is a theoretical framework that combines quantum mechanics and special relativity to describe the behavior of elementary particles and their interactions. In the context of QFT, the quantum fields themselves are typically described mathematically as operator-valued fields defined on spacetime.

A Hilbert space is a mathematical concept used to describe the state space of a quantum system, where states are represented by vectors and physical observables are represented by operators. In quantum mechanics, the state space of a single particle is often described by a Hilbert space.

In quantum field theory, the state space becomes more complex due to the infinite degrees of freedom associated with fields defined at every point in spacetime. The state space of a quantum field theory is typically described by a Fock space, which is a direct sum of tensor products of Hilbert spaces associated with different numbers of particles. Each mode of the field (corresponding to a particular momentum) can be thought of as a harmonic oscillator, with its own associated Hilbert space.

So, while individual components of a quantum field theory can be described by Hilbert spaces, the full quantum field itself is typically not described by a single Hilbert space, but rather by a more complex structure known as a Fock space.

Maybe this will get the thread back on original tract. Thanks for your comments. I agree that Hilbert spaces are useful for the manipulations of Q Theory, but are more descriptive than fundamental.