frank
I think that it is not necessary for the infinite number of numbers to exist in my mind. All I need to have in my mind is S(n) = n+1. — Ludwig V
Ludwig V
There's a lot that could be said about that. It is tempting to classify some rules as habits. Habits neither have, nor require, any kind of justification. They are what they are and that's all that can be said. Rules, on the other hand, can provide justifications and, just for that reason, are, mostly subject to justifications. Some rules do not have, and do not require, any further justification - especially if they set the standard for right and wrong. So these are like habits in that they do not require justification and unlike habits in that they can provide justification. (I'm sketching here.)If I recall correctly, he specifically said "habit" rather than "rule", which suggests naturalizing logic, and indeed I think that's where he was headed. — Srap Tasmaner
That's true. But as soon as we recognize a tree, and recognise this is a different tree and this is the same tree again, we have have sown the seeds of counting. Not so much in the case of rocks and even less to in the case of clouds.We do not find numbers in nature, not in the same way we find trees and rocks and clouds. Did we then make it all up, our mathematics? Is it just a game we play with arbitrary rules? — Srap Tasmaner
No, I don't think that @Meta has shown that numbers don't exist. I'm inclined to think that he doesn't believe that, either. He has been explicit that he rejects what he calls Platonism, but I don't think it follows that he thinks that numbers do not exist. I'm not sure he even rejects the idea that there are an infinite number of them - since he realizes that we can't complete a count of the natural numbers. I do think that we can't get to the bottom of what he thinks without taking on board the metaphysical theory that he has articulated.If you think Meta has convincingly shown that numbers do not exist, then I suppose that's an end to this discussion. And to mathematics. — Banno
I didn't intend it to be. Surely, it works like this - Aristotle thinks that infinity cannot be real if we cannot complete the count. I intended to say that infinity is real even if we cannot complete the count, because the successor function tells us so.I think that it is not necessary for the infinite number of numbers to exist in my mind. All I need to have in my mind is S(n) = n+1.
— Ludwig V
This is Aristotle's finitism. — frank
Yes, I'm aware of that - and of the startling results that followed when his view was set aside and infinity was treated as real, thus enabling the invention/discover/development of the calculus.Per Aristotle, infinity exists in potential. The actual is always finite. Set theory, by handling infinity as a set, appears to be defying finitism. This is an unresolved issue in phil of math. Someday it may result in a shift in thinking about set theory. — frank
frank
Yes, I'm aware of that - and of the startling results that followed when his view was set aside and infinity was treated as real, thus enabling the invention/discover/development of the calculus. — Ludwig V
Metaphysician Undercover
So you do know that the series is infinite without completing the count of them all. — Ludwig V
And yet, Frodo Baggins exists - in the way that fictional characters exist. They can even be counted. Similarly, numbers exist - in their way. — Ludwig V
I'm not quite sure that I understand you. I think that it is not necessary for the infinite number of numbers to exist in my mind. — Ludwig V
All I need to have in my mind is S(n) = n+1. — Ludwig V
It turns out that the disagreement turns on a metaphysical disagreement. Tackling that needs a different approach. — Ludwig V
If you think Meta has convincingly shown that numbers do not exist, then I suppose that's an end to this discussion. And to mathematics.
But I hope you see the incoherence of his position. — Banno
No, I don't think that Meta has shown that numbers don't exist. I'm inclined to think that he doesn't believe that, either. He has been explicit that he rejects what he calls Platonism, but I don't think it follows that he thinks that numbers do not exist. I'm not sure he even rejects the idea that there are an infinite number of them - since he realizes that we can't complete a count of the natural numbers. I do think that we can't get to the bottom of what he thinks without taking on board the metaphysical theory that he has articulated. — Ludwig V
Srap Tasmaner
it's defined as infinite. — Metaphysician Undercover
The point is that a number is not a thing which can be counted — Metaphysician Undercover
There is a very significant error in the idea that a measuring system could measure itself. — Metaphysician Undercover
Banno
The point is that a number is not a thing which can be counted, it is something in the mind, mental. — Metaphysician Undercover
Banno
Of course, why would say that? it's defined as infinite. That's the whole point. It is infinite and infinite is defined as boundless, endless, therefore not possible to count. So any axiom which states that it is countable contradicts this. — Metaphysician Undercover
Metaphysician Undercover
Now many integers are there between zero and five? — Banno
Mathematics on the other hand takes a bijection between two sets A and
B to mean there is a rule f such that each element of A is paired with exactly one element of B, and each element of B is paired with exactly one element of A. — Banno
The bijection is not assumed, it is demonstrated. — Banno
frank
Again, "integer" is a faulty concept, because it assumes that "a number" is a countable object. — Metaphysician Undercover
Metaphysician Undercover
frank
1. Two views about mathematics: nominalism and platonism
In ontological discussions about mathematics, two views are prominent. According to platonism, mathematical objects (as well as mathematical relations and structures) exist and are abstract; that is, they are not located in space and time and have no causal connection with us. Although this characterization of abstract objects is purely negative—indicating what such objects are not—in the context of mathematics it captures the crucial features the objects in questions are supposed to have. According to nominalism, mathematical objects (including, henceforth, mathematical relations and structures) do not exist, or at least they need not be taken to exist for us to make sense of mathematics. So, it is the nominalist's burden to show how to interpret mathematics without the commitment to the existence of mathematical objects. This is, in fact, a key feature of nominalism: those who defend the view need to show that it is possible to yield at least as much explanatory work as the platonist obtains, but invoking a meager ontology. To achieve that, nominalists in the philosophy of mathematics forge interconnections with metaphysics (whether mathematical objects do exist), epistemology (what kind of knowledge of these entities we have), and philosophy of science (how to make sense of the successful application of mathematics in science without being committed to the existence of mathematical entities). These interconnections are one of the sources of the variety of nominalist views. — SEP
Oh oh, the set {1,2,3} has 3 numbers. :gasp: — jgill
Metaphysician Undercover
I would ask one favor though. Stop capitalizing the P in Platonism. The phil of math view of platonism. Plato pitted opposing ideas against each other, so for instance, in Parmenides, he outlines a lethal argument against the Forms. That's why they use a little p: platonism. — frank
frank
I agree. but my spell check doesn't like little p platonism. And, I count the distinction as unimportant because there really would be no such thing as big P Platonism if we maintained that distinction. Plato pitted ideas against each other so there's no real ontological position which could qualify as big P Platonism. So they end up being the same meaning anyway. — Metaphysician Undercover
Banno
We can make it simpler for you: How many whole numbers are there between one and three?Again, "integer" is a faulty concept, because it assumes that "a number" is a countable object. That's exactly the problem I explained to you. We ought not treat an idea as an individual object. Providing more examples of the same problem will not prove that the problem does not exist. The problem of Platonism is everywhere in western society, even outside of mathematics, so the examples of it are endless. — Metaphysician Undercover
Then show us that other rule. Pretty simple. Set the supposed contradiction out.A rule can contradict another rule within the same system. Saying that there is a rule which allows a specific bijection doesn't necessarily mean that there is not another rule which disallows such. — Metaphysician Undercover
“Countable” is defined as “there exists a bijection with ℕ (or a subset of ℕ).” I bolded it for you. Again, if you think there is a contradiction in that, it is up to you to show it.That's false... — Metaphysician Undercover
Metaphysician Undercover
I think you're discounting the importance of community. If it's not stretching your spine out of shape, you can go along with the rest of the phil of math and write it as platonism. It's a little nod to the deep bonds that hold us together over the millennia as our brothers and sisters try to take freakin' Greenland and what not. — frank
We can make it simpler for you: How many whole numbers are there between one and three? — Banno
Set the supposed contradiction out. — Banno
“Countable” is defined as “there exists a bijection with ℕ (or a subset of ℕ).” I bolded it for you — Banno
frank
This issue is more complicated though. The Neo-Platonists took Plato's name and claimed to continue Plato's school, but their ontology is consistent with what you call platonist. Aristotle's school claimed to be the true Platonists but the Neo-Platonists took the name. So you have to take on the Neo-Platonists, and tell them that they should call themselves Neo-platonists, as not true Platonists. But this problem has been around for millennia, and they do not like being accused of misrepresenting Plato, they like to claim the true continuation of Plato's teaching. — Metaphysician Undercover
Banno
So your argument is that 2 is not between 1 and three.This supposition that you have, that there are numbers between numbers is very problematic. — Metaphysician Undercover
Well, no. You claimed there is a contradiction, repeatedly, but never showed what it was. So go ahead and quote yourself.I did it all ready in this thread, numerous times. — Metaphysician Undercover
"There exists a bijection of N" is the conclusion, not an assumption."There exists a bijection with N" is explicitly saying "N is countable". Are you kidding me in pretending that you don't see this? — Metaphysician Undercover
Banno
He's saying that 2 isn't a thing. — frank
It's a modifier like pink. You can't count pinks because it's not a thing you count. It's nominalism. — frank
Banno
It really comes down to which view best accommodates what we do with math. — frank
Banno
sime
I've tried to follow what you are doing here, but scattered inaccuracies and errors make it very difficult. I gather you want to Cantor’s argument into a constructive or even computational lens. It’s valid in that framework, yet you seem to think it can be taken as refuting classical results about cardinality. — Banno
Metaphysician Undercover
So your argument is that 2 is not between 1 and three. — Banno
Well, no. You claimed there is a contradiction, repeatedly, but never showed what it was. So go ahead and quote yourself. — Banno
But in addition to the usual thngs nominalism rejects, Meta rejects the notion that numbers as values of variables. while nominalists say numbers aren’t abstract objects, they undersntad that they can still be quantified over. Meta says that numbers aren’t things at all — they’re modifiers like “pink”. That blocks: — Banno
frank
Regardless of what you assert, to say that the value represented is an object called "a number" is platonism. — Metaphysician Undercover
sime
"Infinite" means limitless, boundless. The natural numbers are defined as infinite, endless. limitless. All measurement is base on boundaries. To say a specific parameter is infinite, means that it cannot be measured. — Metaphysician Undercover
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