That doesn't make sense automatically because formalism is a program for foundations, platonism is an ontological claim. And idk what post of MU it is. — Lionino
Meaningless word games. The fingers on your hand are a physical instantiation of the number 5. Positive integers have the property that the smaller among them may be physically instantiated. 12 as in a dozen eggs, 9 as in the planets unless an astronomical bureaucracy demotes Pluto. That's one for the philosophers, don't you agree? The number of planets turns out to be a matter of politics, not math or astrophysics. — fishfry
Judged by who? Politicians? Academic administrators? Philosophers? How about by their fellow mathematicians? That's the standard of what counts as math. — fishfry
They're meta-false, as I understand you. They're not literally false. If the powerset axiom is false, you get set theory without powersets. You don't get some kind of philosophical contradiction. You are equivocating levels. — fishfry
A model, not a description. Is that better? — fishfry
a mathematician is an explorer trying to find a path extending knowledge in a particular direction or discovering new directions. — jgill
I see an out. In this para you have stated your aim about the real numbers and the number 5. I don't think I have any interest in this topic. I know it's important and meaningful to you, but it isn't to me. Perhaps I'm to dim to grasp all these philosophical subtleties such as you raise. If so, so be it.
But secondly, and I'd be remiss if I didn't add, that I have formally studied the real numbers and the number 5. That doesn't make me right and you wrong, by any means. What it does mean is that I'm not likely to ever defer to your opinions about the real numbers or the number 5. — fishfry
When it suits my argument. I'm a formalist as well at times. — fishfry
Mathematical philosophies are tools, nothing more. Conceptual tools, frameworks for thinking about the development and structure of math. They aren't "true" or "false," they're just models, if you will. — fishfry
Problem solvers and theory builders. The theory builders don't solve problems at all. They create conceptual frameworks in which others can solve problems. — fishfry
LOL. 1 + 1 and 2 are each representations of the same set in ZF, with "1" and "2" interpreted as defined symbols in the inductive set given by the axiom of infinity; and likewise "+" is formally defined. — fishfry
BUT! Are you telling me that you don't believe in the physical instantiation of the natural number 5? Just look at the fingers on your hand. I rest my case. — fishfry
Why me? — fishfry
If I'm understanding you, I agree. I don't think the mathematical real numbers refer to anything in the world at all. They describe the idealized continuum, something that we have no evidence can exist. — fishfry
Your view of intentionality strips out the essence of intention and swaps it for causality; which of no use when we analyze the intentions of someone. — Bob Ross
The intention is wrapped up, inextricably, with the action; and what is caused is an effect. — Bob Ross
What is intentional is what is related to the intention; and the intention is the end which is being aimed at. — Bob Ross
You can’t implicate someone as intentionally doing something they entirely did not foresee happening just because it resulted from an act of intention towards something else. — Bob Ross
I don’t understand what you mean by a “conscious act” which is not intentional (in the traditional sense of intentionality); and this seems to be the crux of your argument. If I consciously decide to do X, then I intentionally did X—even if X is the end I am trying to actualize. — Bob Ross
Of course not. If I take your position seriously, then it would be; because your view attaches the intentionality of an act to all causality related effects. — Bob Ross
Before we dive into this, I need you to define what you mean by “intention”; because you are using it in very unwieldy ways here. — Bob Ross
The point is that what one knows is relevant to what one is aiming at. — Bob Ross
Was is intentional is not solely about the causation that occurs from a given act: it is more fundamentally about what the person is aiming at. — Bob Ross
I just think you're working yourself up over nothing. I'm losing interest. Can you write less? This is tedious, I find nothing of interest here. — fishfry
Pure math is math done without any eye towards contemporary applications. That's a decent enough working definition. Mathematicians know the difference. — fishfry
Mathematics is whatever mathematicians do in their professional capacity. — fishfry
This is a standard complaint. If math follows from axioms, then all the theorems are tautologies hence no new information is added once we write down the theorems. But that's like saying the sculptor should save himself the trouble and just leave the statue in the block of clay. Or that once elements exist, chemists are doing trivial work in combining them. It's a specious and disingenuous argument. — fishfry
We agreed long ago that 1 + 1 and 2 are not the same string; and many people have explained the difference between the intensional and extensional meanings of a string. Morning star and evening star and all that. — fishfry
What math teacher hurt your feelings, man? Was it Mrs. Screechy in third grade? I had Mrs. Screechy for trig, and she all but wrecked me. It's over half a century later and I can still hear her screechy voice. I hated that woman, still do. When I'm in charge, I'm sending all the math teachers to Gitmo first thing. — fishfry
Whatevs. I can't follow you. And I've already noted that the difference between pure and applied math is often a century or two, or a millennium or two. — fishfry
Now what do I mean by "essentially the same?" Well now we're into structuralism and category theory. Sameness in math is a deep subject. I'll take your point on that. — fishfry
Even so, 5 is one of the real numbers. What do you call it if not an instance? What WOULD be an instance of a real number? — fishfry
Explicity stated in any textbook in mathematical logic. — TonesInDeepFreeze
You agree with me about pure math. — fishfry
You have conceded my point regarding math. I have no other point. — fishfry
Tens of thousands of professional pure mathematicians would disagree. — fishfry
Any two set theorists will give {0, 1, 2, 3, 4} as the definition of 5. That's due to John von Neumann, who invented game theory, worked on quantum physics, worked on the theory of the hydrogen bomb, and did fundamental work in set theory. Now there was a guy who blended the applied with the pure. — fishfry
Can you give an example? I might have not followed you. — fishfry
A type of number. No, don't agree. Real numbers and complex numbers and quaternions are types of numbers. The real number 5 is an instance of a real number hence an instance of a number. It must be so, mustn't it? — fishfry
it is explicitly stated that '=' is interpreted as 'is' in mathematics. — TonesInDeepFreeze
Mathematics adheres to the law of identity, since in mathematics, for any x, x=x, which is to say, for any x, x is x. — TonesInDeepFreeze
Not necessarily. If the side effect is not easily foreseen, then we typically don't consider it intentional; or we might say that it was intentional insofar as the person was aware that there was a chance of it happening and accepting those odds. However, in the case that it is foreseeable or was foreseen (with high probability)(all else being equal), then I completely agree it was intentional: it as indirectly intended, which entails it was not accidental.
You can't say some accidents are intentional: that's like saying some orange squares are not orange. — Bob Ross
The hammer hitting your thumb was not intentional whatsoever prima facie in your example. The act of swinging the hammer, intending to bring about the end of hitting the nail into something, was intentional. — Bob Ross
Now, let's say you foresaw that the hammer might hit your thumb and new this with 20% probability and still decided to carry it out: we would say that you intentionally swung the hammer knowing it may result in an accident, but we would NOT say that you intentionally caused that accident. Now, let's say you foresaw with a 99% probability that you were going to cause the accident instead of what you really intend, then we might say you intended it because of the probabilistic certainty that you had of bringing it about. It depends though, because we might say you are just stupid and didn't realize that it doesn't make sense to carry it out with that high of a probability; or we might say you are unwise (unprudent) for doing it anyways out of (presumably) passion or desire to hit the nail. — Bob Ross
My main point is just that accidents, by definition, cannot be intentional. That's categorically incoherent to posit. — Bob Ross
Now explain this to me ONCE AND FOR ALL. Are we talking about pure math and set theory? Or are we talking about the physical world of time, space, energy, quantum fields, and bowling balls falling towards earth? — fishfry
You can not have it both ways. — fishfry
No. You don't understand how math works, and you continually demostrate that. — fishfry
You finally said something interesting. Is the 5 in your mind the same as the 5 in my mind? I think so, but I might be hard pressed to rigorously argue the point. — fishfry
Is an apple an instance of fruit? Apples don't have a peelable yellow skin. 'Splain me this point. By this logic, nothing could ever be a specific instance of anything, since specific things always differ in some particulars from other things in the same class. — fishfry
When I arrive home in the evening, it makes quite a big difference to me if I return to the same residence or just one that's "equal" to it in value. — fishfry
I think it would be more accurate to say "The apparent unintelligibility is due to a thing's matter or potential." — Ludwig V
I don't think that's quite right. It is true that if the lamp is on, it has the potential to be off, and if the lamp is off, it has the potential to be on. But that's not the same as having the potential to be neither off nor on. — Ludwig V
A lamp, by definition, is something that is on or off, but not neither and not both. There are things that are neither off nor on, but they are not lamps and the point about them is that "off" and "on" are not defined for them. Tables, Trees, Rainbows etc. — Ludwig V
I don't think that's quite right. The LEM does not apply, or cannot be applied in the same way to possibilities and probabilities. "may" does not usually exclude "may not". On the contrary, it is essential to the meaning that both are (normally) possible - but not both at the same time. — Ludwig V
And are there 'vast differences' between Plotinus and Plato? I readily grant at every juncture that your knowledge of the texts greatly exceeds my own, but I had thought it well-established that Plotinus saw himself as no more than a faithful exegete of Plato. — Wayfarer
The substance of these questions has been before you repeatedly and you make no substantive answer. — tim wood
I don't make a distinction between "same as" and "is equal to." In math they're the same. If you have different meanings for them, it does not bear on anything I know or care about. — fishfry
No, orderings are not "contradictory properties." Technically, an order on a set is another set, namely the set of pairs (x,y) for which we mean to denote that x < y in the ordering. The ordering is distinctly and noticeably separate from the set it applies to. — fishfry
That distinction has no meaning or relevance in my understanding of the world. "equal" and "the same as" are entirely synonymous. — fishfry
Would you agree that "number" is a general abstraction and that 5 is a partcular instance of number? Isn't that the most commonplace observation ever? — fishfry
Red is not an instance of the concept of color? How do you figure that? — fishfry
"The axiom given above assumes that equality is a primitive symbol in predicate logic." — fishfry
Humans, more than most animals, are "animated by purpose". — Gnomon
If the lamp is neither off nor on at 12:00 (and still exists) then it must be in a third state of some kind. — Ludwig V
Accidents are never intentional; but evolution doesn't operate on accidents. — Bob Ross
And then again, we have no evidence that the mathematical real numbers are even a decent model for time. The real numbers are continuous, but nobody knows if time is. — fishfry
It's a shame we use the word "approach," because many are confused by that. — fishfry
dissing me with passive aggressive faint praise as a way to diss the other poster — TonesInDeepFreeze
Yikes. — TonesInDeepFreeze
As they can relate in multiple ways, it would seem, according to you, they can have more than one order. Thus you say they have one order and no other, and yet many. — tim wood
Very nice. How toxic of you, MU. But note that what I "put down" is just what you put down, I merely asking you to make sense of it. — tim wood
It appears, then, that one and one and no other is actually a many. — tim wood
It is not any more a contradiction for a set to have more than one ordering than it is a contradiction for a person to own more than one hat. — TonesInDeepFreeze
Set consisting of three balls colored red, white and blue. They also have differing weights. What is THE order? Just curious. — jgill
And exactly what order is that? — tim wood
Ok this is interesting. My quote was, "Sets are subject to the law of identity." So that if X is a set, I can say X = X without appealing to any principle of set theory.
Tones convinced me of that. Now you say that he only sophisted me. How so please? If X is a set, how is X = X not given by the law of identity? You have me curious.
You think I'm a victim of Tones's sophistry. That is an interesting remark. — fishfry
Set theory is a mathematical structure. The analogy is:
Set theory is to group theory as a particular set is to a particular group.
But a set is a mathematical structure too, since the elements of sets are other sets. — fishfry
This is true about kids in playgrounds, NOT mathematical sets. You have informed me that you don't like real-world analogies so I no longer use them. Mathematical sets have no inherent order. — fishfry
A temporal extension. You are saying it only applies to things that exist in time? Meaning not sets? I don't think that's right. Any set is identical to itself and also equal to itself by virtue of the law of identity. — fishfry
Tones did explain that to me, but not via sophistry. He asked me to prove the transitivity of set equality. Once I attempted to do that, I realized that I needed not the axiom of extensionality, but its converse. And that converse is true by way of the law of identity from the underlying predicate logic. This I discovered for myself when Tones pointed me to it. — fishfry
I tell you that a set has no inherent order; and that the set of natural numbers in its usual order; and the set of natural numbers in the even-odd order say -- 0, 2, 4, 6, ...; 1, 3, 5, 7, ... is exactly the same set. It is a different ordered set, because in an ordered set, the order is part of the identity of the set. In a plain set, it's not. This is how mathematicians play their abstraction game. — fishfry
Yes, well, discussions of denying LEM don't interest me much. I'll agree with that. But I've come by it honestly. I've made a run at constructivism and intuitionism more than once. I've read Andrej Brauer's "Five Stages of Accepting Constructive Mathematics." It doesn't speak to me. The paragraph you quoted is a little above my philosophical pay grade. Perhaps you can explain its relevance to the topic at hand. — fishfry
I don't see why. If X is a set, then X = X by identity. — fishfry
There is no time in set theory. Mathematics is outside of time, or talks about things that are outside of time. — fishfry
But given particular instances of set theory; that is, sets; we can ask if they are equal to each other or not.
So I promise not to say that the universe of sets is equal to the universe of sets. Though the category theorists will probably disagree with you. — fishfry
You are distorting what I said. ANY particular set is a particular instance of the concept of set, as any particular apple is an instance of the concept (or category) of apple. That causes no problem. — fishfry
This is where I think it makes sense to look for the original sense of Plato's eidos, the forms - not in some fanciful ethereal 'Platonic heaven' but in the underlying patterns of causal constraint which imposes order on possibility. — Wayfarer
The crank is so mentally deficient that he can't see that it's not a contradiction that "there are 24 orderings of a set" does not imply "all those orderings are the same". — TonesInDeepFreeze
Now like a child with an attention disorder, the crank asks me whether the members of a set are abstractions or concretes, after I explicitly said that they can be either, and I gave explicit examples. Is the crank not able to read? — TonesInDeepFreeze
Moreover, I did not say that an element of a set cannot be a concrete thing. The set of pencils on my desk has only concrete things as members. — TonesInDeepFreeze
I never said that 24 orderings are the same or that they are equal. That would be a ridiculous thing to say. Indeed it is my point that they are not the same. There are 24 different orderings. Of course they are not all the same orderings. The crank is so mentally inept that he can't distinguish between (1) there are 24 different orderings that each have the property of being an ordering of a certain set and (2) all those orderings are the same. — TonesInDeepFreeze
Design and purpose are inextricably linked, and can be used to two ways: the intentionality of an agent and the expression thereof in something, or the function something. I mean it in the latter sense when it comes to humans.
That my eye was not designed by an agent, does not entail it does not have the function, developed through evolution, of seeing. In that sense, it is designed for seeing. If you wish to use "design" in the former sense strictly, then I would just say that one should size up to their nature, and their nature dictates their functions. — Bob Ross
I never said any such thing. I've said the opposite — TonesInDeepFreeze
Actually I am wrong about that TonesInDeepFreeze showed me the error of my ways. All sets satisfy the law of identity. If I have a set X, I may write X = X by way of the law of identity. I do not need the axiom of extensionality for that. Perfectly clear to me now. — fishfry
The law of identity applies to sets. So this line of argument is null and void. — fishfry
Yes, very good. A group is any mathematical structure that obeys the axioms for groups. A set is any mathematical object that obeys the axioms for sets. — fishfry
The relevance of all this to the principles of excluded middle and contradiction is as follows. Peirce wrote that “anything is general in so far as the principle of excluded middle does not apply to it,” e.g., the proposition “Man is mortal,” and that “anything” is indefinite “in so far as the principle of contradiction does not apply to it,” e.g., the proposition “A man whom I could mention seems to be a little conceited” (5.447-8, 1905). If we take Peirce to have meant LEM and LNC, then it appears that he wanted to deny the principle of bivalence (according to which all propositions are true or else false) with regard to universally quantified propositions, and that he meant to claim that existentially quantified propositions are both true and false. But why think that “Man is mortal,” which seems to be straightforwardly true, is neither true nor false? And why think that one and the same proposition, “A man whom I could mention seems to be a little conceited,” is both true and false? Once we see what Peirce meant by “principles of excluded middle and contradiction,” we see that this is not what he was claiming. — Digital companion to C. S. Peirce
Sets are subject to the law of identity. — fishfry
YOU have problems with the empty set. I have no such problems. — fishfry
An element is a set in a set theory without urelements. We say x is an element of y if we can legally write x∈y
∈
. Nothing could be simpler. — fishfry
Cinderella is a particular fairy tale character. She doesn't exist either, but she is an INSTANCE of the category of fairy tale characters.
Fairy tale characters are abstract universals, and Cinderella is an abstract particular. — fishfry
I was going to reply that slowing down isn't stopping. I didn't realize that the slowing down was a convergent series. Perhaps slowing down can be stopping. — Ludwig V
Well, we could if we wanted to do. But why would we want to? Apart from the fun of the paradox. Mind you, I have a peculiar view of paradoxes. I think of them as quirks in the system, which are perfectly real and which we have to navigate round, rather than resolve. Think of the paradoxes of self-reference. Never permanently settled. New variants cropping up. — Ludwig V
I think it must be pretty clear that any expression of the relation is just the expression of an idea. — tim wood
With our E(arth) and M(oon) in mind, let's imagine a snapshot of our local space - no time passing. — tim wood
Your claim, then, seems to be nothing more than a claim - a belief on your part. And I give beliefs as beliefs a pass. If you want more, you shall have to make clear how it can be more. — tim wood
But what about that rock? If it's the one that is the crank's head, then it is indeed empty and there is only one ordering of the set of its particles, which is the empty ordering. — TonesInDeepFreeze
The elements of sets have no inherent order. — fishfry
Sets have no meaning whatsoever, other than that they obey the axioms of set theory. — fishfry
This was in response to your denial of the empty set. Tell me exactly -- and be extremely clear and specific, please -- tell me what other rule of set theory is contradicted by the empty set. — fishfry
I have explained to you the ontology of sets many times. They are mathematical abstractions. — fishfry
You know, I am not sure I agree that sets are universals. My understanding is that "fish" is a universal, and the particular tuna that ended up in this particular can of tuna I bought at the store today is a particular instance of the category or class of fish.
Sets are not like that at all.
I did ask you a long time ago to explain what you meant by universals, and you snarked off at me. And now you come back at me claiming that sets are universals. Explain to me what you mean by that.
The concept of a set is a universal. The set of rational numbers is a particular set, of which there is exactly one instance. — fishfry
LOL. Oh man you're crackin' me up. The set of rational numbers most definitely has a cardinality of ℵ0
ℵ
0
, because of Cantor's discovery of a bijection between the rational numbers and the natural numbers. — fishfry
Exactly and well put. I've given the crank that same explanation. He will never understand it, because he wants to not understand it. If he found himself understanding it one day, then he would face the crisis of seeing that he's been confused and in the dark for years and years (decades?). — TonesInDeepFreeze
...the set whose members are all and only the bandmates in the Beatles... — TonesInDeepFreeze
However, we may speak of the set of particles of the rock... — TonesInDeepFreeze
That's where the thought experiment isn't a piece of fiction like a fantasy. Aesop's Fables are also not just a piece of fiction; we are meant to draw conclusions about how to live our lives from them. So "It's just a silly story" is not playing the game. This story wants us to draw a conclusion about how reality is. — Ludwig V
So, instead of rejecting the idea that time is infinitely divisible, you are turning to Hume and arguing that anything can happen. Maybe you are on stronger ground here. I think some people would feel that you are importing more reality than the rules allow. But I can't be dogmatic about that because I don't really know what the rules are - and I'm certainly not going to argue with Hume - perhaps I'm just shirking a long complicated argument, because I don't think he's right, even though he has a point. — Ludwig V
Yes. I don't know how this would play with actual Relativity Theory. But in any case, I don't think that resolves the problem. Why? Because it doesn't actually get Achilles to the finishing line. In the case of Thomson's lamp, it doesn't get to the crunch point when the time runs out. In other words, it postpones, but doesn't resolve, the issue. — Ludwig V
That's why I insist that the convergent sequence is not about space or time, but about the analysis of space and time. — Ludwig V
