Because we can prove what the result would be, we do not have to actually carry out the pairing of every rational number with a natural number. Proof is a further refinement of prediction, beyond even calculation. Of course it's impossible to count the elements of an infinite set as you would the elements of a finite set. But for the results we're interested in here, you do not need to. That is the point. We already know what the result would be if it were in fact possible. — Srap Tasmaner
I can put it another way: what you cannot calculate, you must deduce. — Srap Tasmaner
We don't need much ontology. Quantification will suffice. — Banno
How do you know that the natural numbers go on for ever? — Ludwig V
So they are countable in the sense that some of them can be counted and we cannot find any numbers in the sequence that cannot be counted. — Ludwig V
Ah, so this is about actual and potential infinities. My problem with that is that I don't see how the idea of a possible abstract object can work. — Ludwig V
The philosophical parameters for the debate what it means for a mathematical (abstract) object to exist are well enough defined, so that's the debate we are really involved in. — Ludwig V
A grasp of what the problem actually is, rather than misrepresenting what it arises from, might be helpful. — Mww
There's a category error that involves thinking that because we can't start at one and write down every subsequent natural number, they don't exist. — Banno
It is also well-known that those issues do not arise in the same way at the macro scale. — Srap Tasmaner
Logic and mathematics are mental tools or technologies, habits of mind, that we have developed for dealing with things at the macro scale. — Srap Tasmaner
This is unsurprising since our mental lives consist, to a quite considerable degree, of making predictions. Logic and mathematics enable us to figure out ahead of time whether the bridge we're building can support six trucks at once or only four. — Srap Tasmaner
Which leads, at last, to my point, such as it is: there is something perverse, right out of the gate, about the insistence on "actually carrying it out". It misses an important point about the value of logic and mathematics, that we can check first, using our minds, before committing to an action, and we can calculate instead of risking a perhaps quite expensive or dangerous "experiment". ("If there is no handrail, people are more likely to fall and be injured or killed" -- and therefore handrail, without waiting for someone to fall.) — Srap Tasmaner
The natural numbers turn out to go on forever, and we can prove this without somehow conclusively failing to write them all down. — Srap Tasmaner
To see the demonstration that the rational numbers are equinumerous with the natural numbers and complain that it is not conclusive because no one can "actually do them all" is worse than obtuse, it is an affront to human thought. — Srap Tasmaner
Allow me to apologize if my previous replies came off as an attempt to ridicule you. That was not my intention. — Esse Quam Videri
I see that what I've said so far has not convinced you. That's understandable. That said, I'm not sure I have the ability to express my critique any more clearly than I already have. I say that not in an attempt to blame you for misunderstanding me, but more as an acknowledgement of my own limitations in that regard. I still stand by my arguments, but I'm not sure how to productively move the discussion forward from here. Thanks. — Esse Quam Videri
The formal definition I provided to you (or similar variation) is the one you will find in many of the standard textbooks on Real Analysis, Set Theory and Discrete Mathematics that discuss countably infinite sets. This is why it confuses me when you say that you don't believe that this is the standard formal definition of "countably infinite". — Esse Quam Videri
Likewise, and for the same reason, I am also confused by your insistence that the definitional existence of a bijection requires that the bijection be temporally or procedurally executable. Within the global mathematics community it is commonly understood and accepted that procedural execution is not a requirement for definitional existence. This is why you will not find such a requirement listed in the aforementioned textbooks. This is also why I previously stated that adding this requirement would amount to something like an external constructivist critique of the dominant paradigm. — Esse Quam Videri
How on earth do you imagine all the natural numbers? — Srap Tasmaner
If you re-read my reply carefully you will see that I did not say that mathematicians do not use the word "capable", but that they use it in a different way. — Esse Quam Videri
"A is countable" means "∃f such that f is a bijection between A and ℕ". That's it. There is nothing procedural in this definition. That was my point. — Esse Quam Videri
This is just one example of the way in which, when you change one feature of a language-game (conceptual structure), you often have to change the meaning of other terms within that structure.
So, "countable" in the context of infinity cannot possibly mean the same as "countable" in normal contexts. In the context of infinity, it means that you can start counting the terms and count as many as you like, and there is no term that cannot be included in a count; the requirement that it be possible to complete the count is vacuous, since there is no last term. It's not a problem. — Ludwig V
For example, how about "there is no rational that you cannot place on the number line"? — Ludwig V
...and the only difficulty remaining is that concerning how a community of substances is possible at all, the resolution of which lies entirely outside the field of psychology, and, as the reader can easily judge from what was said in the Analytic about fundamental powers and faculties, this without any doubt also lies outside the field of all human cognition. — "Critique
The key word in all this seems to be "all". You might as well bold it each time you use it. — Srap Tasmaner
You disagree, and so far as I can tell only because anyone who tried to do this would never finish. — Srap Tasmaner
what are you referring to with this phrase, "all the positive integers"? I know what I would mean by that phrase; I genuinely do not know what you mean. — Srap Tasmaner
This statement of yours is neither a theorem, nor a definition nor a logical consequence of anything from within the formal system. This is a philosophical assertion grounded in a procedural interpretation of "capable" that is foreign to the mathematics. All you are saying here is that the impossibility follows from your definition of "capable", and that you think your definition is the right definition. This is an external critique. At no point have you derived a contradiction from within the system. Therefore, nothing you have said so far justifies the claim that the system is inconsistent. — Esse Quam Videri
I'm just wondering if you think somewhere in the rest of the paragraph (following the bolded sentence) you have provided an argument in its support. Is this the post you will have in mind when someone asks and you claim to have demonstrated that "Nothing is capable of being put into one-to-one correspondence with all of the positive integers"? Because it's just an assertion of incredulity followed by a lot of chitchat. (I think you have in your mind somewhere an issue of conceptual priority, but it's not an actual argument.) — Srap Tasmaner
This does not negate our knowing it by other means. Kant is only talking about reason, rational thought. We are acquainted with the noumenon through our presence in the world. — Punshhh
Exactly. "Countable" means something very specific within the formalism. The critique provided amounts to a rejection of that notion, not a derivation of contradiction from within the system. — Esse Quam Videri
It all depends on how one defines "countable" — jgill
All you’ve claimed so far is that mathematicians are working with a notion of infinity that you don’t accept, and you’ve given some philosophical reasons for rejecting it. — Esse Quam Videri
The problem is that this is a philosophical objection, not a mathematical one, and as such it doesn’t justify the claim that the mathematical notion of infinity is contradictory. The mathematical definition is perfectly sound relative to the formal system in which it is embedded. — Esse Quam Videri
By analogy: suppose we’re playing a game of Chess and, on your turn, you legally move your queen from d1 to a4. Suppose I respond to your move by saying: “that move doesn’t make sense because in real life kings are more powerful than queens and so only kings should be able to move like that”. That may be a fine external critique of the rules of Chess, but I haven’t thereby shown your move to be illegal. Given the established rules, it was a perfectly valid move. — Esse Quam Videri
Likewise, your objection to the mathematical notion of infinity is a meta-level objection. It doesn’t undermine the internal coherence of mathematics as it is standardly practiced. At most, it shows that the standard mathematical notion of infinity conflicts with your own metaphysical views. — Esse Quam Videri
f you wanted mathematicians to take this challenge seriously as mathematics, it would require proposing an alternative formal framework built around your accepted notion of infinity and showing that it does at least as much mathematical work as the existing one. As things stand, no such reason has been given for abandoning the standard definition. — Esse Quam Videri
Excellent use of the chess analogy. — Banno
I don't agree. Measurement is not comparison. Measurement is finding the numeric value of the measured objects or movements. — Corvus
Yes, I know, but the thing’s identity as itself, the first law of rational thought, is not what the transcendental idea “in-itself” is about. — Mww
But there’s no change in the “in-itself”, so any measure in units of time, are impossible. — Mww
Rather what the OP specifically referenced, which is the infinite numbers between infinitely minute numbers. — LuckyR
I would agree with you if the object of this discussion were 'real' infinity as a 'real-world phenomenon'.
I find this 'real' infinity uncomprehensable, and so any speculation about it's properties, seems, well, at the very least, dubious. — Zebeden
Still, I would argue that if the 'orthodox' view of mathematical infinity solves more problems than it creates, then so be it. — Zebeden
This is why the discussion keeps looping. If you want to move the discussion forward you need to either (1) derive (not assert) an actual contradiction within the accepted mathematical framework (per ↪Banno) or (2) reject the standard framework and present a coherent alternative (e.g. intuitionism, finitism, non-classical logic, etc.). — Esse Quam Videri
At this point there is nothing of substance left to discuss. — Esse Quam Videri
Both of you have raised worries about the “doability” of bijection for infinite collections, which suggests a rejection of the identification of existence with formal definability and consistency. That’s a substantive philosophical position. But if that’s the objection, then it isn’t a matter of showing that the usual definitions lead to contradictions (they don’t), but of rejecting the underlying framework. — Esse Quam Videri
Framed that way, the disagreement would look less like an accusation about the failure of proof and more like a clash of foundational commitments, which is where I suspect the disagreement really belongs. — Esse Quam Videri
Magnus's objections are framed as an internal problem with a proof, when they should be framed as external problems with the process being used. — Banno
If Magnus rejects the very idea of infinite totalities... — Banno
So constructivism will not help Magnus here. He must resort to finitism - the view that why for any number we can construct its successor, we can't thereby construct the infinite sequence N
. — Banno
To say that the empirical world “arises also from the cognitive faculties of the subject” is correct if it is understood transcendentally rather than causally. The subject does not produce empirical objects, but it provides the necessary conditions under which anything can appear as an object in a unified world.
Kant is not dividing labor between the subject (general concepts) and Nature (particular things). Instead, he is saying that Nature itself is Nature as appearance, which exists only in relation to the subject’s forms of intuition and categories. To invoke “Nature herself” as the source of particular empirical things is to speak as if we had access to Nature as it is in itself. From Kant’s point of view, that is precisely the illusion his critical philosophy is meant to dispel. — Joshs
So, yes, the “in-itself” idea can only refer to itself, but from which occurs a problem for the other cognitive faculties, for a reference to itself contains no relations, hence would be worthless as a principle. — Mww
But I will call out the language of “intelligible objects.” I think this is where a deep metaphysical confusion enters. Expressions like “objects of thought” or “intelligible objects” (pace Augustine) quietly import the grammar of perception into a domain where it no longer belongs. They encourage us to imagine that understanding is a kind of inner seeing of a special type of thing. I'm of the firm view that the expression 'object' in 'intelligible object' is metaphorical. (And then, the denial that there are such 'objects' is the mother of all nominalism. But that is for another thread.)
But to 'grasp a form' is not to encounter an object at all. It is an intellectual act — a way of discerning meaning, structure, or necessity — not the perception of something standing over against a subject. Once we start reifying intelligibility into “things,” we generate exactly the kind of pseudo-problems that Kant was trying to dissolve. — Wayfarer
Not really, but ignoring the infinite level of irrelevance of the topic is a pretty important omission. — LuckyR
Well, no. It is defined as f(n)=n−1 and then shown to be a bijection. — Banno
Yep. that's what a proof does. — Banno
Noumenon means literally 'object of nous' (Greek term for 'intellect'). In Platonist philosophy, the noumenon is the intelligible form of a particular. Kant rejects the Platonist view, and treats the noumenon primarily as a limiting concept — the idea of an object considered apart from sensible intuition — not as something we can positively know. And it’s worth remembering that Kant’s early inaugural dissertation already engages directly with the Platonic sensible/intelligible distinction. — Wayfarer
I am not asking for anything. I am just stating that any act of reading measurements is involved with some sort of measuring tools. You cannot read size, weight or time with no instruments or measuring tools. The measuring instruments or tools become the part of reading measurements. You cannot separate them. — Corvus
To take photos of the speeding cars, it uses camera vision, not the radars. Radars are used for mostly flying objects in the sky and aeronautical or military applications, not for the speed traffic detection.
Why and how does your ignorance on the technology proves that I am wrong? — Corvus
This is a good question. Measurement of time is always on change. That is, the changes of movement of objects. It is not physical length. It is measurement of the duration on the start and end of movement the measured objects.
Think of the measurement for a day. It is the duration of the earth rotating once to the starting measurement geographical point. It takes 24 hours. Think of the length of a year. It is the set point where the earth rotates around the sun fully, and returns to the set point, which the duration of the movement is 365 days.
Think of your age. If you are X years old now, it must have counted from the day and year you were born until this day. For this measurement, you don't need any instruments, because it doesn't require the strict accuracy of the reading / counting. However, strictly speaking, we could say that your brain is the instrument for the reading. — Corvus
Hmmm…..the in-itself is purely conceptual, as a mere notion of the understanding, thus not real, so of the two choices, and in conjunction with conceptions being merely representations, I’m forced to go with imaginary. But every conception is representation of a thought, so while to conceive/imagine/think is always mind-dependent, we can further imagine such mind-dependent in-itself conceptions as representing a real mind-independent thing, by qualifying the conditions the conception is supposed to satisfy. This is what he meant by the thought of something being not at all contradictory. — Mww
If you could think of some measuring instrument, you will change your mind I am sure. — Corvus
Think of the speed detection machine for detecting cars driving over the speed limit on the road.
The machine monitors the road via the camera vision, and reads the speed of every passing cars. When it detects cars driving over the set speed limit in the machine, it will take photo of the car's number plate, and sends it to the traffic control authorities, from which they will issue a fine and warning letter with the offense points to the speeding driver. — Corvus
Time doesn't have physical existence itself. It is measurement of perceived duration. — Corvus
The OP is correct, yet incomplete. — LuckyR
You can use the entire set of natural numbers as your measuring stick, or its power set if that that's not enough, or the power set of the power set, and so on. — SophistiCat
Counting infinite sets works the same way, except that you have to set aside certain other assumptions that hold for finite sets but not for infinite sets. — SophistiCat
Why is it so difficult to see it? — Corvus
I can't think instead of you, Banno. If you can't do it, that's fine. But don't make it look like it's the other person's problem. — Magnus Anderson
You should get on well with Meta. — Banno
Earth’s magnetic field and gravitational field are in the same space. But the particles associated with those fields are not in each other’s spaces. — Mww
But I see your point. It was Feynman in a CalTech lecture, who said fields could be considered things, insofar as they do occupy space. But you know ol’ Richard….he’s somewhat cryptic, if not facetious. — Mww
The first statement says that space and time are relevant to or operative in some domain, which doesn't rule out that they are also relevant to or operative in other domains. The second says they are relevant to and operative in only one domain. If you cannot see the difference in meaning between the two statements then I don't know what else to say. — Janus
I was trying to make you understand what measurement means. — Corvus
Why can’t two things occupy the same field without occupying the same space?
If the sun’s light is a field projected from itself, how can it occupy the same field as that which receives it? — Mww
"Space and time are the pure forms of intution"―not dogmatic.
"Space and time are nothing but the pure forms of intution"―dogmatic. — Janus
I'll be quick on the quantum answer as I don't want to distract from your real point. The reason we measure as a wave vs an point is again a limitation of measurements. Lets go back to the waves of the ocean for example. We have no way of measuring each molecule in the wave, and even if we did, we would need a measurement system that didn't change the trajectory of the wave itself. I agree, its not all 'lumbering instruments', sometimes its just the limitation of specificity in measurement. Even then, such specificity is often impractical and unneeded. Fluid dynamics does not require us to measure the force of each atom. — Philosophim
You say I think Kant is dogmatic, and I do because Kant, having said we can say nothing about the in itself, inconsistently and illegitimately denies that the in itself is temporal, spatial or differentiated in any way, which is the same as to say it is either nothing at all or amorphous. He would be right to say that we cannot be sure as to what the spatiotemporal status of the in itself else, and that by very definition. — Janus
So I get that it can rightly be said that the in itself cannot be known to be spatial, temporal or differentiated in the ways that we understand from our experience inasmuch as we have defined it as being beyond experience, but it does stretch credibility to think that something which is either utterly amorphous or else nothing at all could give rise to the world of phenomena. Kant posits it simply on the logical grounds that if there are appearances then there must be something which appears. — Janus
You misunderstood my point. I never said or implied, just 2 folks agreeing on something is objective. My idea of objectivity means - widely or officially accepted by scientific tradition or customs in the world. — Corvus
Measurement is not idea. It is reading of the objects in number. Numeric value read by the instruments i.e in case of time or duration, it would be stop watch or clock. The instruments are set for the universal reading methods in numeric value, which is objective knowledge on the objects. — Corvus
Your confusion seems to be coming from the fact that you misunderstands the ideas of "measurement". Please read the proper definition from my previous post. It is not property of property. Measurement is always in numeric value of the objects read by the instruments. — Corvus
True enough, but my response would be….my experiences are not on so small a scale. I remember reading…a million years ago it seems….if the nucleus of a hydrogen atom was the size of a basketball, and it was placing on the 50yd-line of a standard American football field, its electron’s orbit would be outside the stadium. Point being, there’s plenty of room for particles to share without bumping into each other. And even if the science at this scale says something different, it remains a fact I can’t seem to get two candles to fit in the same holder without FUBARing both of ‘em. — Mww
You can list them in a sequence, 1/1,1/2, 1/3, 2/3, 1/4, and so on, and so you can count them - line them up one-to-one with the integers. — Banno
That’s actually on point. It’s very close to Bergson’s argument about clock time: what gets measured is not concrete duration itself, but an abstracted, spatialized parameter extracted for practical and mathematical purposes. Precision applies to the abstraction — not to the lived or concrete whole. But then, we substitute the abstract measurement for the lived sense of time. — Wayfarer
No two things can be in one space, but any one thing can be in two times. — Mww
Where it does appear to be controversial is insofar as it calls into question the instinctive sense that the universe simply exists “just so,” wholly independent of — and prior to — any possible apprehension of it. But again, that is a philosophical observation, not an argument against science. It is an argument against drawing philosophical conclusions from naturalistic premises. — Wayfarer
Isn't the measurement objective? — Corvus
Measurement is agreed way of setting and counting the figures of objects, be it size, weight or time. — Corvus
If it is not objective, then everyone will have different way of measurement on days, hours, minutes, distance, size, weight etc, which will make Science and daily life chaotic? — Corvus
It is. If you read the OP as saying it isn’t, then you’re not reading it right. — Wayfarer
Isn't the measurement objective? The feel, knowing and perception of time is subjective, but any measurements are objective i.e. by watch or clock, isn't it? Your 1 hour must be same as my 1 hour, and for the folks in the down under, and the folks in the whole world. — Corvus
The observer knows there is activity independent from the observer”. He does indeed. — Wayfarer
Nothing like that is required. What appears mysterious is not some hidden feature of the world, but the fact that the conditions which make the world intelligible are not themselves part of what appears, but are provided by the observer. That is exactly what “transcendental” means: essential to experience, but not visible within it. — Wayfarer
It's a measured reality - and that is a world of difference. 'One second' is a unit of time. As are hours, minutes, days, months and years. But (to put it crudely) does time pass for the clock itself? I say not. Each 'tick' of a clock, each movement of the second hand, is a discrete event. It is the mind that synthesises these discrete events into periods and units of time. That's the point you're missing. — Wayfarer
But the point is, the observer is watching, measuring, deciding on the units of measurement. — Wayfarer
I looks like we both have an uneasiness with possible world semantics. I think your unease is more with the metaphysics, while mine is with the application. The PI sections you had mentions, 253 to 256 are typically associated with Wittgenstein's argument around private language. Should this extend to possible world semantics? At first glance, I would say "no". Possible worlds are not suppose to be a private language. In PI, a private language is about language only a single individual understands that refers to purely private inner experiences. — Richard B
He does not say this in the quote I mentioned from N&N. What he says is "Don't ask: how can I identify this table in another possible world, except by its properties? I have the table in my hands, I can point to it, and when I ask whether it might have been in another room, I am talking, by definition, about it." — Richard B
Physics can describe relations between states using a time parameter, but that parameter by itself does not amount to temporal succession. A mathematical ordering does not yet give us a meaningful before and after. The fact that most fundamental physical equations are time-symmetric illustrates the point: the time parameter in physics functions is an index of relations between states, not an account of temporal succession or passage. Direction, duration, and the sense of "before" and "after" enter only at the level of interpretation, description, and experience. Hence the philosophical problem of "time's arrow", which is understood to be absent from the equations of physics. — Wayfarer
"Let's call something a rigid designator if in every possible world it designates the same object, a nonrigid or accidental designator if that is not the case. Of course we don't require that the objects exist in all possible worlds" — Richard B
Kripke's example, I like it because it seems rather apropos for everyday conversations we have about everyday objects. — Richard B
