I imagine a unicorn by picturing a unicorn. — RussellA
"1 = 1" is a mathematical expression. — RussellA
I already did above. The axioms of some given set theory are just rules that you must follow when using that set theory. Different set theories have different axioms and so different rules. Given that there's no connection between using some set theory and believing in the mind-independent existence of abstract mathematical objects, there's no hypocrisy in using some set theory and being a mathematical antirealist. — Michael
Your position is like arguing that it's hypocritical to play chess if I do not believe that the rules of chess correspond to some mind-independent fact about the world. — Michael
You don't need to believe in Platonic realism to use set theory. — Michael
I wonder if mathematical realists and mathematical antirealists have different views about mathematical infinity. I'm a mathematical antirealist. I have no problem with mathematical infinity. The "existence" of infinite sets does not entail the existence of infinities in nature (whether material or Platonic). — Michael
Exactly, you understand the concept using images. — RussellA
There are two different cases.
The first a case of identity where the two 1's refer to the same thing. The second a case of equality where the two 1's refer to different things.
The practical advantage of using identity rather than equality is to distinguish two very different cases. — RussellA
"A mythical animal typically represented as a horse with a single straight horn projecting from its forehead" describes an object, even through the object is fictional. — RussellA
In fact, from my position of Neutral Monism, all objects, whether house, London, mountain, government, the Eiffel Tower, unicorn or Sherlock Holmes are fictional, in that no object is able to exist outside the mind and independently of the mind. — RussellA
My belief is that the mind cannot understand an abstract concept in isolation from concrete instantiations of it, in that, if I am learning a new word, such as "ngoe", it would be impossible to learn its meaning in isolation from concrete instantiations of it. — RussellA
If I wanted to teach you the meaning of the symbol "ngoe", which I know is a concept, how is it possible for you to learn its meaning without your first being shown particular concrete instantiations of it? — RussellA
Given 1 and 1, if the second use of 1 refers to the same thing as the first use of 1, then the proper equation should be 1 = 1. The symbol "=" means identity
Given 1 and 1, if the second use of 1 refers to a different thing as the first use of 1, then the proper equation should be 1 + 1 = 2. The symbol "=" means equality. — RussellA
Can there be a description without an object being described? — RussellA
However we can think of the numbers 1. 6 and 10 as not only abstract mathematical objects but also as natural concrete objects. — RussellA
That raises the question as to how we are able to think of something that is abstract, disassociated from any specific instance (Merriam Webster – Abstract). For example, independence, beauty, love, anger, Monday, ∞
∞
, 2–√
2
and the number 6.
George Lakoff and Mark Johnson in their book Metaphors We Live By propose that we can only understand abstract concepts metaphorically, in that we understand the concept of gravity by thinking about a heavy ball on a rubber sheet.
Thereby, we understand the concept of independence by remembering the feeling of leaving a job we didn't like. We understand the concept of beauty by looking at a Monet painting of water-lilies. We understand the concept of infinity by thinking about continually adding to an existing set of objects. We understand the concept of 2–√
2
by thinking about the number 1.414 etc etc. We understand the concept of 6 by picturing 6 apples.
IE, we can only understand an abstract concept metaphorically, whereby a word or phrase literally denoting one kind of object or idea is used in place of another to suggest a likeness or analogy between them (Merriam Webster – Metaphor). — RussellA
It is exactly the point that it is not a mathematical expression, so mathematics is not called on to account for its intensionality. More generally that ordinary mathematics is extensional, and we don't require that it also accommodate intensioncality. That is how it is relevant. — TonesInDeepFreeze
Later, hopefully, I'll have time and motivation to dispel a number of misconceptions in a catalog of them you've posted lately. — TonesInDeepFreeze
Doesn't this problem, soluble by set theory, assume "objects", such as the object "a person who can speak English"?
If the number "1" does not refer to an object, what does it refer to? — RussellA
For example:
Mark Twain = Samuel Clemens — TonesInDeepFreeze
Are you serious? — TonesInDeepFreeze
In mathematics, equality and identity are the same. — TonesInDeepFreeze
While "=" is commonly understood to denote equality in basic arithmetic and algebra, its use to signify identity in formal logic or set theory arises from the need to express relationships between objects or sets in a precise and rigorous manner. — Banno
However, in more advanced mathematical contexts like set theory, "=" is sometimes used to signify identity, — ChatGPT
I mean that all makes sense, although my understanding was that the question of whether or not space-time is infinitely divisible was an open one. — Count Timothy von Icarus
Ok. So we still have no explanation of how you came to misapprehend "=". — Banno
Is Metaphysician Undercover a product of the New Maths? :wink: — Banno
Infinity pools can indeed be awesome — ssu
I am not sure if this is so much a problem with mathematics though as it is with how it gets applied to the sciences and philosophy. It seems to me that infinite divisibility might be worth investigating even if it doesn't accurately reflect "how things are." — Count Timothy von Icarus
You have mentioned, for example, that the limit concept is flawed, although it works well most of the time. But I don't recall your argument beyond that point. A more complete knowledge of space and time and points and continuity? Oh yes, something about the Fourier transform and the Uncertainty principle. What are your suggestions to fix that up? Intuitive mathematics? Remind me where doing something specific makes it better. — jgill
Except incompleteness (in the sense of the incompleteness theorem). — TonesInDeepFreeze
Here's actually some advice to all non-mathematicians (from a non-mathematician):
If you really can ask an interesting foundational question that isn't illogical or doesn't lacks basic understanding, you actually won't get an answer... because it really is an interesting foundational question!
Yet if the answer is, please start from reading "Elementary Set Theory" or something similar then yes, you do have faulty reasoning. — ssu
And sometimes people post questions about mathematical subjects that have bearing on philosophy, such as about infinities, incompleteness and computability. — TonesInDeepFreeze
What is the proper interpretation of the cosmological constant Λ? I understand that it corresponds to a vacuum energy density, pervading all reality. Such energy is called dark energy, I gather. Since I'm sketchy on field theory, I don't know how this goes, but somehow this energy density produces a repulsive force beween any two objects in spacetime (within each other's lightcones?). Matter remains cohesive because Λ is very small compared to other forces, so that its effects really only show at an intergalactical scale (megaparsec). — DanCoimbra
ow, somehow this leads to the expansion of the Universe even in the case where the Universe is finite and bounded, which is a possibility considered by cosmologists. In this case, the Universe is increasing in total size, but not increasing *into* anywhere, so it becomes bigger because it has more internal spatial structure. This is what I meant. Why do you think this is incorrect? — DanCoimbra
I just think if mathematical axioms are to be selected, they have to be such that they do not lead to what is contradictory to Existence/Truth (or just semantics in general). — Philosopher19
If a mathematician or a philosopher decides on an axiom or theory that requires belief in the following (or at least logically implies it or leads to it): Nothing can be the set of all things (which logically implies Existence is not the set of all existents), or one infinity is a different bigger than another (or is a different quantity than another), I believe that axiom or theory should be disregarded or at least viewed as contradictory to Existence/Truth (or at least contradictory to the semantic of infinity). — Philosopher19
What the Universe's expansion means, whether it is infinite or not, is that its local energy density is decreasing. In other words, there is more spatial structure between each of its internal field excitations (particles, energy). — DanCoimbra
So true. The OPs lay out belief systems in one form or another, and sometimes they don't budge. Which I find acceptable in Metaphysician Undercover's pronouncements, for he dwells with the ancients as they ponder space, time, and points and curves - although he balks at 1+4=5 and has little patience with Weierstrass and his limit ideas: admittedly useful, but fundamentally flawed. But I see where he is coming from there. Others, like this thread, are more or less unmovable in their opinions, which clash with standard mathematics. How you deal with the frustration of offering knowledge to those unwilling to accept it is admirable. — jgill
I tried dealing with 1. and 2. earlier, in mathematical analogues, but there was no interest. I could easily deal with 3. as well, but that takes the thread away from the spectacular leap from a first cause being something imaginable to an existential realm. — jgill
Suppose someone produces an axiom. Will it not be the case that that axiom will either be contradictory in relation to certain truths or consistent in relation to certain truths? Existence determines what is true and what is false. Whether any belief or axiom highlights truths or is contradictory to truth is determined by Existence/Truth. If not, there is no truth or semantics to work with to deduce further truths. — Philosopher19
Of course: nuclear reactions have emergent aspects by themselves, but you should distinguish these from emergent chemical features.
You can of course lump everything together and say that the universe, with everything in it, is emergent as a whole. But that means that the various properties of the universe are obscured. — Ypan1944
My belief is that we can't just produce axioms. We can only recognise truths about Existence such as 1 add 1 equals 2 or the angles in a triangle add up to 180 degrees or one cannot count to infinity. — Philosopher19
Nuclear reactions have nothing to do with the features of an atom or molecule. For reactions between atoms or molecules, only the "outside" of an atom (i.e. the outermost electrons of the atom) plays a role. The emergent feature of an atom or molecule depends only on its outermost electron configuration. — Ypan1944
One is free to propose different axioms that prove differently. — TonesInDeepFreeze
I don't agree with you. The features of an atom are totally dependent on the electron configuration of the atom, which you can describe with quantummechanics (harmonic oscillator etc.). The internal structure of the nucleus is irrelevant. You only need to know the electric charge of the nucleus. — Ypan1944
Also in chemical reactions, only the electron configuration of the participating atoms or molecules is important. — Ypan1944
One might argue that the latter encompasses imagining that the count to infinity is complete, but one cannot imagine such a thing. — Philosopher19
The way set theory proves there exists a set with all and only the natural numbers is by an axiom from which we prove that there exists a set with all and only the natural numbers. — TonesInDeepFreeze
Then why do you think bijection requires counting? — Banno
In my opinion, this addition by Bedau is superfluous: you do can actually describe the properties of an emergent phenomenon with "normal" physics, where its substructure is usually irrelevant, so a form of "coarse graining" will happen (f.i. with Bohr's atomic model the substructure of the atomic nucleus is irrelevant, only the electric charge of the nucleus plays a role; and you need a new theory (namely quantum mechanics) to describe that phenomenon) — Ypan1944
Supervenience is therefore completely different from "downward causation". — Ypan1944
Problems occur if you consider the elements of a set to not be themselves sets. Set theory only talks about sets. It does not, for example, talk about individuals.
The lists only list other lists... — Banno