Showing posts with label Paradox. Show all posts
Showing posts with label Paradox. Show all posts

Thursday, January 23, 2025

Freedom

is the freedom to say that 2 + 2

is no more nor less than the number of ones in (1 + 1) + (1 + 1)

How could that be what freedom is?

Who would deny that that is what 2 + 2 is?

And how would their denying it get in the way of our being free?

Surprisingly, it is the experts on numbers who deny it.

A hundred years ago, academic mathematicians redefined the terminology of arithmetic in order to lose an arithmetical puzzle in that translation, because although the puzzling arithmetic does make sense if there is a God like the Trinity who geometrizes continually (see below for the details), academic mathematicians could find no other way of making sense of that arithmetic, and academia was becoming increasingly atheistic in the twentieth century, especially in subjects that used a lot of mathematics (the sciences had started to get atheistic in the second half of the nineteenth century because of an agnostic biologist, Charles Darwin).

Now, academia should not have become so atheistic, because insofar as that arithmetic only makes sense if there is a God, it proves that there is a God (and that arithmetic had been discovered in the second half of the nineteenth century by a Lutheran mathematician, Georg Cantor, who thought that God had revealed it to him).

However, that proof was hidden by those mathematical redefinitions, and by related redefinitions of words like proof, logic and truth, because of a related logical puzzle discovered by an atheist aristocrat, Bertrand Russell, at the start of the twentieth century. Still, maybe that proof will not remain hidden for another hundred years (God does seem to get better results on longer timescales). In any case, the truth will set you free.

For the details of the proof, click on this link: Freedom

That link opens an eight-thousand-word Google Document called "Freedom" in a new window.

Friday, November 08, 2024

On the Hiddenness of God

I recently emailed my book, The Hiddenness of God, to hundreds of academic mathematicians, to see whether or not mathematicians would be interested in the proof buried beneath the foundations of their subject, and I have had some replies already. The following conversation has been edited, but it is fairly typical, in case you were wondering (as I was) what mathematicians would think of my proof.

Mathematician: Russell's paradox (and Epimenides' before him) demonstrates simply that the concept of "truth value" that many logicians had assumed to be well-defined on all statements, and which works well most of the time, must in fact have a few limitations. When we talk about truth values too loosely, plain English hides the fact that we're discussing a function from the class of propositions to the set {T,F} that may not in fact be wholly defined. It's no more mysterious than the discovery that division by 0 can't be defined except by giving up several arithmetic properties that are otherwise unproblematic. Russell simply shows a similar restriction for truth values of self-referential statements. This is well-understood.

And Cantor's theorem isn't even a paradox: it just shows that if we define an ordering by "size" on infinite sets, then the rationals and the reals are in different size classes - and why shouldn't they be? Our ability to "comprehend" either is ill-defined (this is where plain English lets us down): we do not know everything even about large finite numbers (which digit appears most often in 9^(9^(9^(9^(9^9))))?) and we know a very great deal about the real numbers, more numerous than the natural numbers though they are.

While Russell's paradox did do that, the heap paradox and the liar paradox had done it thousands of years earlier. And while Cantor's theorem is indeed not a paradox, it exists within axiomatic set theory. Cantor's paradox arises for the numbers that Cantor was working with, which were essentially the same as the numbers that we learn about at school. There is an obvious and unambiguous meaning to the word "two": two is the number of things in any collection that has as many things in it as the sum 1 + 1 has units in it.

Mathematician: I think the heap paradox is most easily interpreted as showing the axiom that one grain less than a heap is still a heap to be inconsistent. Heapiness is problematic in other ways as well. If we base our definition on general opinion, we more or less have to test it by asking an observer "is this a heap?" and the answer may depend on the observer. If we don't appeal to opinion, there's no reason not to define a heap as a thousand grains or more of sand, or sand grains piled at least five deep.

And while what you said is true for "two" there are more real numbers (in the usual sense) than there are definitions in finite strings of characters... and this happens precisely at the spot we're interested in.

Plain English is good enough for the definition of "two," though; and similarly, for an arbitrary counting number (even though most counting numbers are too big for us to imagine anything about them other than that they are counting numbers). And Cantor's paradox arises for arbitrary subcollections of subcollections of [...] subcollections of counting numbers. The real numbers are complicated (and Richard's paradox is interesting) but irrelevant to Cantor's paradox. As for the answer to "is this a heap?" I think that it can depend on the observer, and that that is one of the reasons why some piles of sand are only heaps as much as they are not heaps. Insofar as they are heaps, removing a single grain of sand would make a negligible difference to that. And for such a pile, "that pile is a heap" would be true only as much as it was not true. And similarly, the liar paradox shows that there are self-referential statements that are true only as much as they are not true. So, Russell's paradox is more like the liar paradox (and the heap paradox) than Cantor's paradox.

Mathematician: I think the heap paradox is somewhat different in that it can be dealt with by saying that "well, it seems that we need to sharpen our definition of a heap. A heap will be any collection of sand numbering more than ten grains, stable, and at least a quarter as tall as it is high." That's roughly what Cantor did with infinities... a fairly small patch on existing math. The first was a paradox, and not the second, only because people had more preconceptions about heaps. Cantor's result is more a proof by contradiction, eliminating a wrong turning in an exploration of new territory. If Eubulides of Miletus had been researching novel ways to store sand (insight - we don't need a bucket!) he might have used the sorites paradox similarly. The liar paradox can't really be explained away by inventing a better liar: it needs the concept of truth that underlies all philosophy to be redefined. Similarly, Russell's paradox involved a complete revamping of basic set theory.

I don't think that the heap paradox can be dealt with by saying that we need to sharpen the definition of "heap" because similar paradoxes occur with almost all of our words (as Russell observed) and because our words simply have the meanings that they have: if we redefine what "truth" means, then we are no longer talking about the truth of our words. I suppose that Cantor's paradox is the proof by contradiction that you think it is if there is no God, but is the proof by contradiction that I think it is (a proof that there is a God) if we should not redefine what "truth" means in order to avoid an inconvenient proof.

Mathematician: It's true that if we take "Cantor's paradox" as a standalone result, rather than as the obvious (in retrospect) conclusion of his construction of sets of demonstrably different cardinality, it looks more like Russell's paradox. That's not the angle I'm used to seeing it from, but I think I see your point. Nonetheless, in Cantor's case we don't have to redefine "truth", we merely have to redefine "set" so that some things we would have naively called sets are "classes" with a smaller set of permitted construction rules. As for the relevance to God: I am not a believer, but quite happy to argue hypotheticals. I agree with Aquinas that any god that exists must be bound by the laws of logic. These are the same laws of logic that bind us: and I see no reason why using a definition of "set" that Cantor showed to be inconsistent could be a divine attribute, let alone why we should want it to be so. Aquinas says in effect that, regarding logic, what's good enough for Cantor (if Cantor is right) is good enough for God. You don't get around Cantor by supposing "theological unions" of sets that somehow differ from those of set theory (or, if you do, you must explain their properties fully and equiconsistently with ZFC or some other well-defined system).

I agree that we should be bound by the laws of logic, and I take that to mean that we cannot just make those laws up. And I am certainly not trying to get around Cantor by supposing theological unions (whatever they are). I am questioning his assumption that mathematical collections must exist timelessly. Cantor chose to believe in the existence of collections that were inconsistent, rather than give up that assumption! Mathematicians can of course use any definition of “set” and “class” that they like, but there is still the paradoxical behaviour of mathematical collections (in the logical sense) to explain. Cantor’s paradox showed that his conception of set was inconsistent, but his conception included the assumption that mathematical collections exist (insofar as such things can be said to exist) timelessly. Incidentally, although Russell found his paradox while he was thinking about Cantor’s paradox, I don’t think that Cantor’s paradox is like Russell’s paradox.

Mathematician: My view is that the word "exist" is not used in mathematics in the sense that Mount Everest is and Alma Cogan isn’t (as the guy on the Monty Python record put it). It's an axiomatically-defined predicate in mathematical theories and metatheories (parallel lines exist in the Euclidean plane, they do not exist in the projective plane). From this viewpoint, I don't see time/timelessness as having anything to do with mathematical existence (I suppose one could take a time-dependent Platonist view where pi really was three in Old Testament times, but that is not how I see it).

For most mathematicians nowadays, mathematical existence is indeed existence within an axiomatic structure, and for such structures it is consistency that matters. And within set theory, there is only Cantor’s theorem. But for numbers like the counting numbers and the number of all the counting numbers, and so on, it is logic that matters: such numbers are essentially properties of logically possible collections (you and I are two people, and we would have been two possible people had we never existed, and the properties of that “two” are logically prior to any axiomatic model of them). And if it is logically possible for there to be a God, then there are all the numbers (in that sense) that give rise to Cantor’s paradox. That is how I have been able to show that if it is logically possible for there to be a God then there is a God, because it is only if there is a God that such numbers could possibly be getting more numerous (and it is only in the last hundred years that mathematicians would have denied that such numbers were part of mathematics).

Mathematician: The statement that "numbers are getting more numerous" is, if not downright false, highly ambiguous. Our mathematical knowledge may encompass more numbers, but a given axiom system implies the same numbers yesterday, today, and forever, even if nobody alive at some time understands that. Furthermore I hold, with (for instance) Aquinas, that it is a logical necessity that no deity could change; so, claiming that the creation of new numbers within a fixed axiom system implies the existence of a god is true only ex falsi quodlibet. Apart from that major objection, if your argument did prove the existence of some entity X, I think (again, hypothetically) that it would fall far short of showing that this X was what was generally called "a god," let alone a specific faith's God.

The numbers in “numbers are getting more numerous” do not exist within any axiom system, but as a consequence of there being numbers of things in the world (such as us two). Axiomatic models of them are timeless, but they themselves are properties of logically possible collections of things, so it is a matter of objective fact whether they are timeless or not. And while we naturally assume that they (and logical possibilities generally) are timeless, it is conceivable that they (and some other logical possibilities) are not timeless if there is a God who is not timeless. As for your belief that if there was a God then that God would have to be above and beyond time and change, I suppose that you have a good reason for believing that, but as I do not know what that reason is, I cannot say why it is not a valid reason (and similarly for your reason for believing that X could not be called a God, unless it is the same reason). I have thought a lot about the reasons that are in the literature, and none of them are valid when it comes to the God that Cantor’s paradox shows exists (which did not surprise me because a lot of the religious believers who take God to be above and beyond time and change would also say that He is above and beyond our logical abilities).

Mathematician: You would seem to be saying that there's an argument showing, on the basis of some axiom system, that some number (call it Stigma) exists... and that at some time in the past the same argument was not valid, or was valid but did not show that Stigma existed. A fun science-fiction idea, but in reality if we pick at it, expanding the argument out to a long but finite list of axiomatic steps and going through it a step at a time, there's a step that somehow didn't work then and does now. But that step is supposedly an instance of an axiom, so the axiom set has changed. Gods whose powers vary in time (depending on who's stolen whose hammer today) are more at home in comic books than in philosophical arguments; when I said "god" I meant the sort of god that modern philosophy usually considers, whose view of the universe is in some sense ultimate and synonymous with reality. If the power of such a god were greater today than yesterday, it would have to have been less than it might have been yesterday. Which, as Spinoza would have said, is absurd.

I too meant the God whose view of the universe is the universe. And I agree that the power of such a God cannot increase, or decrease. However, the knowledge of such a creator would increase as a matter of logical necessity whenever any particular thing was created (as I show in the first “chapter” of my first email). As for your interpretation of what I was saying in terms of an axiom system, the existence of the most basic numbers (1, 2, 3 etc.) does not have to be existence within any axiomatic system, even if there is a God. The existence of such numbers could be the logical possibility of there being collections of that many things (which is why my argument is a logical argument based on Cantor’s original paradox, which he discovered before mathematicians and philosophers axiomatized numbers and collections) [...]

Sunday, November 13, 2022

💥Cantoring away from being Russelled

Twenty-five years ago, as I was getting my masters in mathematics, I was surprised to find an unsolved puzzle about infinity at the heart of modern mathematics. Some of my first thoughts were published in philosophy journals, so I went on to do a masters in philosophy. I got it with distinction, and by thinking laterally as well as logically I found the solution and decided to write it up as a book for a general reader with no background in philosophy, logic or mathematics. Five years later, it is down to 25,000 words.
In the book (which was 28,000 words in July, and which I will re-post when I get it below 10,000 words), various logical puzzles are described and solved because the only perfectly logical solution to one of those puzzles—the puzzle about infinity—is only a logical possibility if there is a logical kind of God. In short, my book amounts to a perfectly logical proof that there is such a God.
      A hundred years ago, the mathematical puzzle was proving to be so puzzling that mathematicians translated the whole of mathematics into a new "language" (akin to a programming language) in order to lose it in that translation. And that sea-change to academic mathematics trickled down to school mathematics in the form of the new math. Which you may have heard of, because it was quite controversial fifty years ago. The mathematicians’ responses were logical enough, but this puzzle is essentially a logical puzzle. And philosophers like Bertrand Russell responded to it by modernizing logic.
      For a hundred years, scientific philosophers have been treating logical thinking as though it was a kind of computing, as something that might be done better on a computer. By explaining these logical puzzles properly, my book will revitalize philosophy. My book may also help to defuse America’s "culture war" by making logic more interesting to religious people while simultaneously showing that atheism is not really very scientific. Indeed, it is not very progressive: how could people growing up in a world with profound problems possibly acquire enough wisdom to change their world for the better? On a more mundane note, scientific research will progress in directions that are more realistic as a result of my book, so my book could herald the next scientific revolution. And of course, a lot of people will simply find it helpful to know that there is a reasonable sort of God.

Monday, February 14, 2022

The God No One Wanted

(That is the new title of my book :-)

1. The Lie of the Land
introduction | expectations | descriptions

2. The Way of Things
Cantor’s paradox | set theory | the proofs

3. Proof of Probability
too many things | the shape of time | God

4. Reasonable Doubts
just bad math | deductions | explanations

5. Doubting Reason
the final straw | Russell’s paradox | truth

Friday, December 10, 2021

Truth


Truth
(three thousand words) will be
section 3 of chapter 5 of my book:
The Way of Things

Monday, December 06, 2021

Russell's Paradoxes


Russell's Paradoxes
(two and a half thousand words) will be
section 2 of chapter 5 of my book:
The Way of Things

Sunday, December 05, 2021

Heaps


Heaps
(two and a half thousand words) will be
section 1 of chapter 5 of my book:
The Way of Things

Friday, November 12, 2021

Impossibly Many Things


Impossibly Many Things
(one thousand words) will be
section 2 of chapter 3 of my book:
The Way of Things

Thursday, October 14, 2021

Proofs


Proofs
(five and a half thousand words) will be
section 3 of chapter 2 of my book:
The Way of Things

Sunday, October 03, 2021

Infinities


Infinities
(two thousand words) will be
section 1 of chapter 2 of my book:
The Way of Things

Monday, July 12, 2021

Progress on "The Way of Things"

My book has been getting bigger and bigger over the past year (it is now over a hundred thousand words) but it seems ready to tidy up, so I will be posting the tidied up sections one by one and linking each post to the section titles in last July's The Way of Things, which can serve as a contents page.

Tuesday, July 14, 2020

The Way of Things


1. Introduction

2. The Way of Things

3. Extraordinary Evidence

4. A God Hypothesis

5. Exceptional Logic

Saturday, September 01, 2018

Curry's Paradox


Last year’s new SEP entry on Currys paradox followed in Haskell Curry’s footsteps by saying nothing about where our reasoning goes wrong in such informal versions of the paradox as the examples in the introductory section of that entry, the first of which was as follows:
Suppose that your friend tells you: “If what I’m saying using this very sentence is true, then time is infinite”. It turns out that there is a short and seemingly compelling argument for the following conclusion:

(P) The mere existence of your friend’s assertion entails (or has as a consequence) that time is infinite.

Many hold that (P) is beyond belief (and, in that sense, paradoxical), even if time is indeed infinite.

[...]

Here is the argument for (P). Let k be the self-referential sentence your friend uttered, simplified somewhat so that it reads “If k is true then time is infinite”. In view of what k says, we know this much:

(1) Under the supposition that k is true, it is the case that if k is true then time is infinite.

But, of course, we also have

(2) Under the supposition that k is true, it is the case that k is true.

Under the supposition that k is true, we have thus derived a conditional together with its antecedent. Using modus ponens within the scope of the supposition, we now derive the conditional’s consequent under that same supposition:

(3) Under the supposition that k is true, it is the case that time is infinite.

The rule of conditional proof now entitles us to affirm a conditional with our supposition as antecedent:

(4) If k is true then time is infinite.

But, since (4) just is k itself, we thus have

(5) k is true.

Finally, putting (4) and (5) together by modus ponens, we get

(6) Time is infinite.

We seem to have established that time is infinite using no assumptions beyond the existence of the self-referential sentence k, along with the seemingly obvious principles about truth that took us to (1) and also from (4) to (5).
That may look rather formal to you, but formal logic is not even logic (it is mathematics); the above is just very well laid out. Note the two uses of modus ponens, the two sets of three steps, with the first three steps, (1), (2) and (3), all beginning “Under the supposition that”. You should note that because we cannot always use modus ponens within the scope of a supposition, e.g.:

(a) Under the supposition that modus ponens is invalid under a self-referential supposition, (A) implies (C).

(b) Under the supposition that modus ponens is invalid under a self-referential supposition, (A).

With (a) and (b) we have, under the supposition that modus ponens is invalid under a self-referential supposition, a conditional and its antecedent, but it would of course be absurd to use modus ponens within the scope of that supposition, to obtain

(c) Under the supposition that modus ponens is invalid under a self-referential supposition, (C).

There was, then, at least one step in the above argument for (P) that stood in need of some justification, i.e. the step to (3). Were no other step deficient in justification we could conclude, from the absurdity of (P), that the step to (3) was invalid.

Of course, it would be more satisfying to see where precisely that step lacked justification, so presumably we need an analysis of what would in general count as justification for such a step. For now, note that in order to get to (3) we used modus ponens under the supposition that k is true, which was no less self-referential than the supposition that modus ponens is invalid under a self-referential supposition. In the step to (3) we had k being true instead of (A) implying (C), and “k is true” instead of (A).

To progress, we need to step back, I think, because I suspect that the reason why we find (P) to be beyond belief is that the above argument for (P) has exactly the same logical structure as a clearly invalid argument for the obviously false (Q):
Let your friend say instead: “If what I’m saying using this very sentence is true, then all numbers are prime”. Now, mutatis mutandis, the same short and seemingly compelling argument yields (Q):

(Q) The mere existence of your friend’s assertion entails (or has as a consequence) that all numbers are prime.
My suspicion is based on the fact that one could conceivably have a valid argument for

(S) The mere existence of “happy summer days” entails (or has as a consequence) that time is infinite.

For a start, the mere existence of some words can entail the actual existence of something important, as when Descartes proved that he existed: I think, therefore I am. But furthermore, there is a surprisingly valid argument from the existence of “happy summer days” to the probable existence of a transcendent Creator of all things ex nihilo (this links to that), and it might only take some tidying up to get to (S), because such a Creator is an omnipotent being endlessly generating a temporal dimension. (Such a Creator could possibly have a logical existence proof, because of its unique ontological status.) And of course, were there a valid argument for (S), then there would be an identical, equally valid argument for (P).

Anyway, a six-step argument for (Q) that is identical to the Curry-paradoxical argument for (P) would have, in place of k, some such l as “If is true, then all numbers are prime”. And is likely to be about as true as not, because (i) it is about as true as not that a contradiction follows from a statement that is about as true as not, since such a statement is about as false as not, and also because (ii) one informal meaning of is the obvious meaning of the liar sentence “is not true”, which is, if meaningful, about as true as not, according to my The Liar Proof. And of course, our logic is naturally suited to that part of our language where propositions are either true or else not true, exclusively and exhaustively. For a proposition that is otherwise, we have natural clarification procedures that enable us to construct new propositions that are more suited to logical reasoning. So, it seems likely that propositions that might be about as true as not should be ruled out from the use of modus ponens within the scope of a too-self-referential supposition (to say the least).

Curry’s paradox entered into the analytic philosophy of the Forties, where the logical paradoxes were in general thought to be reasons for replacing our informal logical reasoning with formal logical reasoning (via the mathematical philosophy of formal languages), on such grounds as that (i) one would not expect primates, even highly evolved primates, to be able to reason perfectly, and (ii) the physical sciences use mathematics to get to the underlying physical laws. However, why would such primates not take themselves to be reasoning perfectly adequately; and why should I be doing mathematics when I am really doing philosophy?

Saturday, August 18, 2018

The Modal Paradox

Here in the actual world A we have a ship, let us name it the good ship Theseus, made of 1000 planks. Our first intuition X is that the same ship could have been made of 999 of these planks plus a replacement for plank #473. In possible-worlds terms that means there is another world B where the same good ship Theseus exists with all but one plank the same as in our world A, and only plank #473 different. But then in world B one has a good ship Theseus made of 1000 planks, and by the same sort of intuition, there must another world C where the same good ship Theseus exists with all but one plank the same as in the world B, but with plank #692 different. That means for us back in world A there is another world C where the good ship Theseus exists with all but two planks the same as in our world A, but with planks #473 and #692 different, so one could have two planks different and still have the same ship. The same sort of considerations can then be used to argue that one could have three planks different, or four, or five, or all 1000. But that is contrary to our other intuition Y [a ship made of a thousand different planks would have been a different ship].
     The modal paradox resembles well-known paradoxes of vagueness, such as the heap and the bald one, for which proposed solutions are a dime a dozen — except that here what seems to be vague is the relation of identity. And the idea that ‘is the very same thing as’ could be vague is for many a far more troubling idea than the idea that ‘heap’ or “bald’ is vague. Indeed, according to many, it is an outright incoherent idea.
From John P. Burgess, "Modal Logic, In the Modal Sense of Modality" pp. 40-1.
     In the fourth line Burgess says "by the same sort of intuition," which is a relatively weak sort of thing to say, and so it might be where the paradoxical reasoning started to go wrong. Our original intuition X was that in the actual world A, Theseus could have had one plank different and still have been the same ship. We know, equally intuitively, that X coheres perfectly well (somehow) with the intuition, Y, that in the actual world A, Theseus could not have a thousand planks different and remain the same ship. Whereas the ship in B is not exactly the same as the ship in A. And the meanings of all our words are rooted in A. The further we get from A, the more vague we might expect our meanings to become.
     In the first line of the second paragraph Burgess observes that proposed solutions to the paradoxes of vagueness are "a dime a dozen" and that means, I think, that anything I might say is bound to pointlessness; but, onward and upwards. And it is certainly the case that "the very same thing" often equivocates, as in the case of the famous clay statue: if that thing is squashed then, while it is the same lump of clay, it is no longer a statue at all. So let us look at a very different formulation of the ship paradox, one that does not involve modality at all. The following is by Ryan Wasserman, "Material Constitution", §1:
[...] the story of the famous ship of Theseus, which was displayed in Athens for many centuries. Over time, the ship’s planks wore down and were gradually replaced. [...] Suppose that a custodian collects the original planks as they are removed from the ship and later puts them back together in the original arrangement. In this version of the story, we are left with two seafaring vessels, one on display in Athens and one in the possession of the custodian. But where is the famous Ship of Theseus? Some will say that the ship is with the museum, since ships can survive the complete replacement of parts, provided that the change is sufficiently gradual. Others will say that the ship is with the custodian, since ships can survive being disassembled and reassembled. Both answers seems right, but this leads to the surprising conclusion that, at the end of the story, the ship of Theseus is in two places at once. More generally, the argument suggests that it is possible for one material object to exist in two places at the same time. We get an equally implausible result by working backwards: There are clearly two ships at the end of the story. Each of those ships was also around at the beginning of the story, for the reasons just given. So, at the beginning of the story, there were actually two ships of Theseus occupying the same place at the same time, one of which would go on to the museum and one of which would enter into the care of the custodian.
For myself, I do not think that the ship in the museum was the famous Ship of Theseus, I think that what was left of that ship is now the custodian's ship. But I concede that it could be that the museum ship is legally the ship of Theseus. It would then follow that the custodian's ship was not, for legal purposes, the ship of Theseus. So I think that there are at least two senses of "ship of Theseus" in play. What we can say about those senses is another matter. Our language is inextricably rooted in the usual events of the actual world. But it could be scientific to know that there are those two senses even before our theories of such senses have become a dime a dozen. And we might find clues as to what we should be saying from related puzzles.
     There are many intuitive puzzles about identity. For one example, suppose that the world that you are in splits into two worlds, so that you are in one while an identical person is in the other. You are the same person as the original you, of course, but so is the person in the other world. So, that other person is the very same person as the original you, who is the very same person as you, and yet that other person is not the very same person as you. So, either personal identity is not always a transitive relation, or else this scenario is impossible. And while the latter is certainly plausible, it seems to me to be the wrong sort of conclusion to draw from this scenario. Knowing whether it is the wrong sort of conclusion to draw or not may well be a prerequisite for getting anywhere with such puzzles as the modal paradox, because intuitions for "is the very same thing as" not ever being at all vague seem to be very similar to intuitions that it must always be transitive.
      For another example, it is conceivable that you change all of the molecules in your body as you eat and shit and eat and shit and so on and so forth; and you would also be aging. You would be the same person, of course; but if another person arrived now, with completely different molecules and a slightly different, older look to you, that would of course be a different person. Being the same person or not is not, it seems, a matter of what one is made of (a thought that is entirely consistent with our being incarnated souls that might possibly reincarnate). And in the real world, where we live our lives, being the same person or not is a matter of identifying someone from descriptions and pictures.

Tuesday, July 31, 2018

On the Sorites


          A drop of water falling on a hill does not wash it away.
So, if we start with a hill, then after a drop of water we still have a hill.
After another drop, we still have a hill; and many repeated applications
of the first, italicised line means that after lots of drops the hill remains.
But, after enough drops the hill will, of course, have been eroded away.

That is basically a Sorites paradox. Similarly, all real-world calculations will, if long enough, become swamped by error bounds. All measurements should come with error bounds, and while a short calculation will result in only slightly larger error bounds on the result, a very long calculation will be useless. Now, logic is supposed to be different, more like Geometry, where given certain lengths, geometrical manipulations can be arbitrarily long. But that will only be the case if the terms that the logic is applying to are definite. In the real world, there is a ubiquitous, if usually very slight, vagueness (it is there because it is so slight: nothing has acted to remove it). Consequently logical arguments that are about real things should not be too long. It is an interesting question, how long they can be; but certainly, those of the Sorites paradoxes are too long.

Thursday, July 26, 2018

The Unbelievable Proof


What follows is a proof of the (probable) existence of God.
     Such an extraordinary claim requires extraordinary evidence, of course, and so this post is a bit long. (But most of the heavy lifting has already been done by those who have been failing, for over a hundred years, to find atheistic explanations of certain basic mathematical facts.)
     Evidence for the existence of God must be extraordinary, of course, but it must also be of an appropriate kind. Suppose we saw letters of unearthly fire in the sky, spelling out a claim that there is a God; the most likely explanation would be pranksters, or, at a push, aliens. Evidence for the existence of the Creator of all things, including such things as the human mind, should therefore include something more like a logical proof. There are already several arguments that claim to be such, e.g. the ontological argument; you might think of the following as another – we could expect there to be several logical proofs, because when we find one proof of a mathematical theorem, there are usually others to be found – although I personally do not think that the ontological argument works as a proof.

What follows is based on the nineteenth century mathematics of Georg Cantor, and in particular, his famous logical paradox.
     Logical paradoxes are chains of thought that seem logical but which take us from self-evident truths to contradictions. Nothing, you might think, could be further from a proof; but it is precisely because logical thoughts take truths to truths, not to contradictions, that it follows that in every such paradox there must be some false assumption(s). The harder the paradox is to resolve, the stronger – and more surprising – will be the chain of thought from the false assumption(s) to the contradiction. A very tough paradox can therefore amount to a rigorous chain of thought that takes some very plausible assumption(s) to a contradiction, thereby proving by reductio ad absurdum the assumption(s) to be – surprisingly – false. In particular, Cantor’s paradox refutes atheism (and classical theism, which I take to be the view that there is a being who is omnipotent, omniscient, immutable and so forth).
     Things that are as Cantor’s famous diagonal argument shows them to be could, just possibly, exist within the creation of a Creator of all things (were that Creator not classically immutable). You will see why below; and while that fact may not seem like much, it yields a reason why there is probably such a Creator because there is very probably no other way in which things as we know them to be could exist. That high probability comes from the fact that mathematicians and logicians have been looking for a more intuitively satisfying resolution of Cantor’s paradox for over a hundred years, working within their background assumptions – atheism, for the most part (although also classical theism, especially in Cantor’s day) – and in all that time they have found no better way of avoiding paradoxical contradictions than the formalization of mathematics and logic.
     Cantor was working on Fourier analysis, in the 1870s, when he found it necessary to extend arithmetic into the infinite, despite various paradoxes. He resolved those paradoxes by extending arithmetic in a rigorously logical way, throughout the 1880s, but sometime in the 1890s he found his own paradox. Naturally he worried that he had refuted his own work, but he had been very rigorous, and so there was little the mathematical community could do – given their background assumptions – but formalize the foundations of mathematics. The question of what numbers really are was left to philosophers; in mathematics, there is no paradox: there are formal proofs, in most axiomatic set theories, that there is no set of all the other sets: were there such a set, its subsets would outnumber the sets, via a diagonal argument (see below), whereas subsets are sets. Formalization enables the paradox to be avoided, but it does not resolve the underlying problem: whenever we have a lot of sets, we do have their collection, because a collection of things is, intuitively, just those things being referred to collectively; and since each of its sub-collections is, intuitively, just some of those sets, we also have all of those sub-collections. Intuitive versions of Cantor’s paradox remain, then, to be resolved.

The following version, in particular, works by way of showing that certain possibilities become more and more numerous (see my earlier sketch of this version). Now, if something is ever possible, then it was always possible; but, possibilities of various kinds can grow in number by becoming more finely differentiated, as you will see in the following two paragraphs. But to begin with, an initial worry might be that even if some possibilities were differentiated in the future, those differentiated possibilities would already exist in spacetime (so that their number would actually be constant). So note that while presentism – the view that only presently existing things really exist – is not popular, it is generally agreed to be logically possible. Let us therefore use ‘time-or-super-time’ to name time if presentism is true, and something isomorphic to presentist time – at a mere moment of which the whole of spacetime could exist – if the whole of spacetime really does exist. The point of that definition is that time-or-super-time might exist even if presentism is false; either way, ever more possibilities could, just possibly, be individuated (in time-or-super-time).
     For a simple example of differentiation, suppose that spacetimes come into being randomly, in time-or-super-time, with some of them happening to be exactly the same as our spacetime. Someone exactly the same as you exists in each of those spacetimes. And of course, each of those identical copies of you was always possible in time-or-super-time. As we consider any one of them, it seems as though there must always have been the individual possibility of that particular person; and certainly, that individual was always possible. But what about the copies of you in future spacetimes? How could their individual possibilities be already distinguished from the more general possibility of someone exactly the same as you? Such copies of you do not yet exist, to be directly referred to, and indeed, they may never exist. So for such random beings, in presentist time-or-super-time, it would not make sense for their particular possibilities to exist. So despite our hindsight, the possibilities of such people must originally have been undifferentiated parts of the more general possibility of someone just like you. It is only with hindsight – after differentiation – that we see the differentiated possibility in the past.
     For an example without randomness, suppose that a Creator in time-or-super-time determines to create a ring of equally spaced, absolutely identical objects. None of those objects can be individuated until the ring has been created, because their Creator does not want to individuate them. So before then there is only the general possibility of such an object. Afterwards there is, for each object, the individual possibility of that object in particular, in addition to that general possibility. Once a particular object exists, there seems always to have been that particular possibility – because that particular object was always possible – even though we know, from the description of this scenario, that it was the general possibility that always existed.

I will be describing how certain possibilities might become more and more individuated by a dynamic (as opposed to immutable) Creator of all things ex nihilo. Creation of things ex nihilo is the creation of things out of nothing; it contrasts with the creation of things made out of some already existing substance (like a sentient computer making a phenomenal world out of computers and human brains). Creation ex nihilo is, at the very least, logically possible. After all, the Big Bang was clearly possible, and for all we know it could have followed nothing physical; for all we know, it could have followed some sort of creativity, such as a person. What we know for sure is that in the world there are physical objects and people. It is not easy to see how real people could be made of nothing but chemicals, but physicalism is of course a prima facie logical possibility; and it is similarly possible that spacetime and everything in it was created by a transcendent person.
     Given that such a Creator is logically possible, the following paradox then shows that the possibilities in question probably do become ever more numerous, because that is probably the only way of avoiding the contradiction derived below (other than simply ignoring it, or in other ways rejecting logic). Furthermore, it is very hard to imagine how those possibilities could possibly become more numerous if there is no such Creator. That is why this resolution of the paradox has for so long been overlooked. And that is how this paradox will show that there is probably such a Creator. So, to my intuitive but rigorous version of Cantor’s paradox.

We should begin with a self-evident truth; and clearly, these words are distinct from each other. That fact is self-evident because that is how we were able to read those words. There are, then, numbers of things; for example, ‘I’, ‘am’ and ‘lying’ are three words.
     Note that pairs of those three words – {‘I’, ‘am’}, {‘am’, ‘lying’} and {‘I’, ‘lying’} – are just as distinct from each other as those words were, because those three pairs differ in just those three words. Similarly, pairs of those pairs – e.g. {{‘I’, ‘am’}, {‘am’, ‘lying’}} – are just as distinct; as are pairs of those, and so on.
     Now, because of that ‘and so on’ we will have infinitely many, equally distinct things, if we can indeed count pairs as things. But is there really something that, for any two things, sticks them together to make a third thing? Put that way, it must seem unlikely. But, for you to pick out any two of our original three words, those two words must have already been a possible selection. Such possibilities can be our third things. In general, a combinatorially possible selection from some things corresponds to giving each of those things one of a pair of labels, e.g. the label ‘in’ if that thing is in that selection, or else the label ‘out’. If two of the labels are ‘in’, for example, we have a combinatorially possible pair. Every combination of as many such labels as there are things in some collection corresponds to some combinatorially possible selection from that collection, and vice versa.

So, let us take ‘{‘I’, ‘am’}’ to be the name of the combinatorially possible selection of ‘I’ and ‘am’ from our original three words, and similarly for the other increasingly nested pairs described above, which we may call, collectively, ‘N’. The following intuitive but rigorous version of Cantor’s diagonal argument proves that for any collection of distinct things, say T, the collection of all the combinatorially possible selections from it, say C(T), is larger than T.
     Informally, two collections are equinumerous – they have the same cardinal number of things in them – when all the things in one collection can be paired up with all of those in the other. So suppose, for the sake of the following reductio ad absurdum, that C(T) has the same cardinality as T. Each of the things in T could then be paired up with a combinatorially possible selection from T in such a way that every one of those possible selections was paired up with one of the things in T. Let P be any such pairing. We can use P to specify a possible selection, say D, as follows. For each thing in T, if the possible selection that P pairs that thing with includes that thing, then that thing is not in D, but otherwise it is, and there is nothing else in D. Since the only things in D are things in T, D is a possible selection, and so it should be in C(T). But according to its specification, D would differ from every possible selection that P pairs the things in T with, which by our hypothesis is every possible selection in C(T). That contradiction proves our hypothesis to be false: C(T) does not have the same cardinality as T. Furthermore, C(T) is not smaller than T, because for each of T’s things there is, in C(T), the possible selection of just that thing; so, C(T) is larger than T.
     As well as N, there is therefore the even larger collection C(N), and similarly C(C(N)) – which is just C(T) when T is C(N) – and so forth. All the things in all those collections are as distinct from each other as our original three words were, because they differ only in things that are just as distinct. Let the collection of all those things be called ‘U’: U is the union of N, C(N), C(C(N)) and so forth. U is larger than any of those collections because for each of them there is another of them that is larger and whose things are all in U. And since there are all of those things, there are also all of the combinatorially possible selections from them, which are just as distinct from each other, and which are collectively C(U). And so on: there is always a larger collection to be found; if not another collection of all the combinatorially possible selections from the previous collection, then another union of every collection that we have, in this way, found to be there. Those steps always take us to distinct possibilities that are fully defined by things that are already there. So, there must already be all the things that such steps could possibly get to.
     The problem is that from all of those things existing, it follows that all of the combinatorially possible selections from them also exist – since they are equally distinct possibilities, fully defined by things that are already there – and there are even more of those possible selections, as could be shown by a diagonal argument, which contradicts our having already been considering all the things that such steps could possibly get to.

Since there are no true contradictions – outside formal logic – something that seemed self-evident in the above must have been false. But the above chain of reasoning was a relatively short argument, from a self-evident premise. It is very easy to survey the whole of the argument and see how rigorous it was. The only lacuna is the one highlighted above: the obscure possibility of those combinatorially possible selections being the end results of more general possibilities becoming individuated. The following proof relies on that being the only lacuna, which you can only determine for yourself by trying – and failing – to find another. Perhaps, for example, there are no such things as possibilities? But were there no logical possibilities, logical thought would become impossible (except in some formal sense), and so we must presume that there are such things. It can be argued that there are not; but similarly, there are those who argue that there is only mind, while others argue that there is only matter. It seems to me to be self-evident that there are phenomena – our experiences – as well as physical things (e.g. those that we experience), and, similarly, that a huge range of non-formal logical thought is possible. And in particular it seems to me to be self-evident that {‘I’, ‘am’} is one of three combinatorially possible ways of making a pair of words (from our original three). Consequently the question is where a principled line should be drawn: where are the joints of nature? The reason why {‘I’, ‘am’} is a possible selection is that ‘I’ and ‘am’ are two of our original three words, and that reason generalises in an obvious way: for any things, in any given collection of things, those things are a possible selection. Note that a logically possible being could select those things from that collection.
     Regarding the possibility of the combinatorially possible selections being the end results of more general possibilities becoming individuated, it is conceivable that the Creator of all things ex nihilo would be able to individuate them because of the unique authority of such a being. Much as the individual possibilities of particular people, in the example above, could not be distinguished from the more general possibility of just such people, not until those people were there to be directly referred to, so it might be that the most unimaginably nested of the combinatorial possibilities are not individuated until such a being individuates them (by thinking of them). They need not be individually possible selections until then because who could possibly make such a selection? There is only the Creator, thinking of them in the absolutely definitive way of such a being. Naturally, such possibilities seem as immutable as the laws of physics, to us; but of course, to a God the laws of physics are mutable.
     There is not much more to be said, about such divine differentiation, though. Creation ex nihilo is totally alien to our experience, so it is essentially obscure. But, it is a relatively clear logical possibility for all that. Analogously, it is quite obscure how atoms of lifeless matter could be arranged so as to make conscious life, but that does not stop materialism being a logical possibility (for all that it might make it seem less plausible). Note that such a Creator could have existed prior to any things at all, because such a being could be, in itself, more like a Trinity than a thing. Such a being could have always known of the most general possibility of things as we know them, before choosing to contemplate creating some such things; and could then have known an awful lot about combinatorially possible selections, nested around those possible things, up to unimaginably high levels of an increasingly nested hierarchy (such levels as standard mathematicians would never contemplate). It makes sense that a being that could create things ex nihilo would know so much about them (and might even enjoy finding out more). Standard set theory would therefore be a very good mathematical model of the more imaginable levels (and of how there are unimaginably high levels, not all of which can be assumed to exist already). (Note that none of the properties of the underlying things would be made variable by the higher levels being variable; on the contrary, each level would be completely determined by those things being distinct things.)

So, since a dynamic Creator is, at the very least, a logical possibility, hence our combinatorially possible selections could, just possibly, be growing ever more numerous. And since there seems to be no other way of avoiding the contradiction, hence those possible selections are probably growing in number. Furthermore, outside the context of the absolute dependency upon their Creator of things created ex nihilo, there is no conceivable way in which those possible selections could grow in number. That is why this resolution has, for so long, gone unnoticed. And that is why it follows that there is – at least probably (in view of that long period of modern thought) – such a Creator.
     The big problem with that conclusion is, of course, that the majority of scientists are atheists. You might therefore be quite sure that there must be a flaw somewhere in the above. The most surprising thing about the above, however, is how scientific it could seem to simply ignore it, even if there is no such flaw. Many logicians take the logical paradoxes to be good reasons for not trusting pre-formal logic (and similarly, pre-formal arithmetic), however rigorously it is applied. After all, we would hardly expect primates – even highly evolved primates – to be perfectly logical. Whereas you might expect that a more formal treatment would find there to be no problem; and indeed, there is no formal paradox. Formal logic does not just look scientific, it reliably delivers desired results.
     Nevertheless, logic – our natural, pre-formal logic – is not so much an option as a necessity. Would highly evolved primates reject their own logic just because it gave them something that had seemed too good to be true? Probably not; but more importantly, it is not really an option. It is only because we believe science to be logical – in the pre-formal sense – that we believe science when it tells us that we are highly evolved primates. It is not because scientific results could be written up in a formal logic. After all, there are formal logics in which true contradictions have been formalised. And while most formal logics do not allow true contradictions, the question is: how could we determine which formal logic to use, except by applying our natural logic, as rigorously as we can? Even letting formal criteria decide the matter would be to have decided pre-formally to do so. Note that we should not do that; such formal criteria as simplicity, for example, might tell us to allow true contradictions. Indeed, the logical paradoxes could all be regarded as straightforward proofs that there really are true contradictions, unless we had already ruled that out. And we should of course rule that out, because things cannot be a certain way while not being at all that way. Being that way is precisely what ‘not being at all that way’ rules out, pre-formally.
     It was one thing to reluctantly replace logic with formal logic, and numbers with axiomatic sets, in order to avoid paradoxical contradictions; it would be quite another to jump at the chance to make such replacements just to avoid the refutation of a strongly held belief. The latter would clearly be unscientific. Of course, you may think that there is no such refutation, that God has been invoked to explain something that may well be explained by science one day. And such God-of-the-gaps arguments are indeed unsound. Before it was discovered that we are on the surface of a massive spheroid orbiting a star, for example, a sunrise might have been explained by invoking God, on the grounds that only a God could cause such an awesome event. My argument, however, is more like the Newtonian connection of the motion of planets with the motion of projectiles. That is because there is, in mathematics, a practice of defining mathematical objects in terms of human constructions; such constructivism is not popular, but it is a valid practice. I am explaining the Cantorian property of things by invoking divine constructivism, not a simplistic miracle. Note that there is no perception in modern mathematics – as there was in the early years of the twentieth century – that Cantor’s paradox might be resolved by future research within the mainstream. Rather, our axiomatic set theories and formal logics are beginning to look more and more like epicycles.
     It might be thought that I do have a God-of-the-gaps argument because I do use God to explain something scientific. So note that there were similar objections to Newton’s invocation of action-at-a-distance, in his explanation of astronomical observations, on the grounds that action at a distance is magical action. Physical action was thought to be action by physical contact (even though the physicality of such contact is primarily phenomenal). Of course, any actual action in the external world will fall under physics. And my finding of a scientific use for the hypothesis of a Creator shows that God can be a scientific hypothesis.
     Euclidean geometry was axiomatised, but that did not make it true; space is what is it. Ptolemaic astronomy could have been axiomatised, but the earth still turns. Standard mathematics is axiomatised; nevertheless, there are numbers of things.

Saturday, March 17, 2018

The Liar Proof


This assertion is not true.
Let that assertion – if it is an assertion – be called ‘L’.
          If L is an assertion – the assertion that L is not true – then L is an assertion that it is not true that L is not true, and so L is also an assertion that L is true. That is unusual, to say the least; but it is clear enough what is being asserted – how else could we know that it had that unusual property? – and so L is fairly clearly an (unusual) assertion. And if L is as true as not (see below), then it is as true to say that L is true as it is to say that it is not, so there is that consistency. Note that L is not a simple conjunction of those two assertions; it is wholly the assertion that L is not true (if it is an assertion), and it thereby asserts that L is true. And note that no assertions are perfectly straightforward; all are to some extent vague, for example.
          Nevertheless, logic seems to take L to a contradiction. (By ‘logic’ I mean that which formal logics model mathematically. Formal axioms are abstracted from informal but rigorous arguments, arguments so rigorous that we regard them as proofs. Were such a proof to include a step that did not correspond to any axiom, we should have a reason to revise our formal logic; we should have no reason to reject the proof.) If L is true – if it is true that L is not true (and that L is true) – then L is not true (and true). But L cannot be true and not true, of course; the ‘not true’ rules out its being true. And so if L must be either true or else not true, then it follows that L is not true. But if L is not true – if it is not true that L is not true (and that L is true) – then L is true (and not true); and L cannot be true and not true.
          So, logic takes L to a contradiction if – and as shown below, only if – we assume that assertions must be either true or else not true. The negation of that assumption is not logically impossible – see below – and so it is that assumption that logic is taking to a contradiction. That assumption is certainly very plausible, of course. To want the truth of a matter is to want things to be made clear. It is to want the vagueness to be eliminated. Nevertheless, there are a variety of abnormal situations where it would be highly implausible for the assumption in question to be true (and L is not a normal assertion). Suppose, for example, that @ is originally an apple, but that it has its molecules replaced, one by one, with molecules of beetroot. The question ‘what is @?’ is asked after each replacement, and the reply ‘it is an apple’ is always given. Originally that answer is correct: originally it is true that @ is an apple. But eventually it is incorrect. And so if the proposition that @ is an apple must be either true or else not, then an apple could (in theory) be turned into a non-apple – some mixture of apple and beetroot – by replacing just one of its original molecules with a molecule of beetroot. And that, of course, is highly implausible.
          What is surely possible, since far more plausible, is that @ is, at such a stage, no less an apple than apple/beetroot mix, that it is as much an apple as not, so that the assertion that @ is an apple is as true as not. That assertion could not be true without @ being an apple, nor not true without @ not being an apple (and we can rule out neither true nor not true, because that is just not true and true). More precisely, @ is likely to move from being an apple to being as much an apple as not in some obscure way that is, to some extent, a matter of opinion. In between true and not true we may therefore expect to find states best described as ‘about as true as not, but a bit on the true side’, ‘about as true as not’ (a description that would naturally overlap with the other descriptions) and ‘about as true as not, but a bit on the untrue side’. For such abnormal situations, formalistic precision would be quite inappropriate, because the truth predicate is indeed suited to the elimination of vagueness. It is much better to say ‘it is as much an apple as not’ instead of ‘it is an apple’ when the former is true, the latter only as true as not.
          But we cannot express L better, we have to understand it as it is. Fortunately, if we do not assume that assertions must be either true or else not true, then from the definition of L it follows only that (if L is an assertion then) L is true insofar as L is not true, and hence that L is as true as not. There is no contradiction, and so either L is not even an assertion (which seems implausible) or else the Liar paradox is a disguised proof by reductio ad absurdum that it is not the case that assertions must be either true or else not true. Note that there is no ‘revenge’ problem with this resolution. E.g. consider the strengthened assertion R, that R is not even as true as not (which is thereby also an assertion that R is at least as true as not). If R is true then R is false (and true), if R is as true as not then R is false (and true) and if R is false then R is true (and false); but, if R is about as true as not, a bit on the untrue side, then it would be about as false as not to say that R was not even as true as not (and about as true as not to say that R was at least as true as not). Greater precision than that would be inappropriate for an assertion as unnatural as R.

Friday, March 09, 2018

Logic

There are many logical paradoxes.
A famous example is the Liar paradox: “This is a lie.”
If that is a lie, then it is a lie that it is a lie, so it is not a lie.
But if it is not a lie, then what it says is false, so it is a lie.
Whereas, if it is not a lie, then it is not the case that it is a lie.
Contradiction! So, our logic gives us paradoxes. But, so what?
Even highly evolved apes would hardly have a perfect logic.

Most modern thinkers think of themselves as highly evolved apes, in a purely material world that just happens to exist. They/we think so because they/we have taken logical looks at the evidence; but, what happens to our image of ourselves as scientific if we can play fast and loose with logic? We want to be very careful in any choice to embrace illogicality in our thinking; we want, ironically, to make a very logical choice about any such thing.

In taking logical looks at the world, we may well have given low prior probabilities to the existence of a Creator, maybe following Richard Dawkins; but, what if there is a logical proof that there is a transcendent Creator? That would change everything! Thoughts that such a proof could not be possible are naturally based on those very low priors, and at the end of the day there is such a proof. Still, were we to simply refuse to countenance the possibility of a transcendent Creator, then any such proof would become just another logical paradox; and such simple refusals are not necessarily illogical:
I see a tree, so I know it is a tree; that is certainly rational. I cannot rule out its being an alien quasi-stick-insect of a very convincing kind, but so what? I have been assuming that it is no such thing; and even now, after thinking of this particular possibility, I still have no idea how unlikely, or likely, it really is, and so I still cannot do any better than to continue to make that assumption. Making it makes my knowledge a sort of gamble, but such is human knowledge in the real world.
And yet, where do we draw the line? If we had a proof that the tree was really an alien quasi-stick-insect, then surely that assumption would then be illogical. What if you have a very good argument for something that I really do not like; can I take that dislike to trump your argument? Surely not. My dislike can of course motivate me to believe that there is probably a fatal flaw in your argument, but I really should be bothered by the excellence of your argument. Surely I should not just exhibit my dislike, and observe that to err is human. Surely we should all assume logic. Even if it is flawed, it is our logic, and so assuming it would just be the most human error; and maybe our logic is not that bad. Let us look again at the Liar paradox:

“The assertion you are currently considering is not true.”
Let that assertion be called “L” so that: L is true if, and only if, L is not true.
Were “true” a vague predicate, L would be true insofar as L was not true,
from which it would follow logically that L was as true as not.
It follows logically that if “true” could be a vague predicate,
then the Liar paradox is actually a proof by reductio ad absurdum
that it is a vague predicate: then, and only then, is there no contradiction.

Is it only then? That is, after all, why this is a paradox. You could say that the meaning of “true” rules out truth being vague; and of course, truth itself is not normally vague, far from it: to want the truth is to want things to be made clear. But Liar sentences are deliberately constructed to be paradoxical, when they are not simply mistakes that should be rewritten to make them clearer. And consider the following, which is similarly far removed from our normal uses of language:

      Consider “It is an apple”
as an answer to the question “What is A?”
      where A is originally an apple,
but has its molecules replaced, one by one,
      with molecules of beetroot.

Originally, “It is an apple” is a correct answer (or in other words, it is true that it is an apple), but eventually it is not. If that answer must be either correct or else not (if that proposition must be either true or else not true), then an apple can be turned into something else (presumably a mixture of apple and beetroot) by replacing just one of its original molecules with a molecule of beetroot, which certainly seems absurd. It is surely possible, since it does seem more plausible, that A is, at such a stage, no less an apple than it is apple/beetroot mix; that it is, at such a stage, as much an apple as not, so that the proposition that it is an apple is as true as not; what else could it be?

Monday, March 05, 2018

The Signature of God

I think belief in God reasonable only if it is based on considerations available to all humans: not if it is claimed on the basis of a special message to oneself or to the group that one belongs.
Anthony Kenny ("Knowledge, Belief, and Faith," Philosophy 82, 381-97)
      So what better signature of the creator of homo sapiens than an elementary logical proof that there is a God? In my last post, I described the argument that given some things, cardinally more selections from them are possible.
      That post ended with a brief description of how that means that paradox arises: we naturally assume that each of the possible selections that such endlessly reiterated selection-collections and infinite unions would or could ever show there to be is already a possibility, that it is already there, as a possible selection; it would follow that they were all there already, that they are collectively some impossible collection of all those possible selections.
      Logic dictates that we have made some mistake; and this version of Cantor's paradox arises because we are considering combinatorially possible selections: that is why the sub-collections that define those selections were able to become so paradoxically numerous, why the paradoxical contradiction did not just show that there are not, after all, so many extra things, over and above the original things.
      My resolution begins by observing that apparently timeless possibilities could, possibly, become more numerous over time; it begins that way because if possible selections are always becoming more numerous, then we would never have all of them. A Constructive Creator could, possibly, make the definitive selections; and if that is the only logical possibility, then that is what has been shown.
      Note that serious mathematicians have taken Constructive mathematics seriously, and when constructed by a transcendent Creator the mathematics would be much more Platonic, and much more Millian. Consider, for an analogy, how God's commands could, just possibly, define ethics. And note that such creative possibilities are not that different to the Creating of mere things ex nihilo, if you think about it: how is such Creation even possible? For us, the laws of physics present immutable limits to what can be done; for a God, such laws are, metaphorically, a brushstroke.
      We live in a world of things, and numbers of things; and for us, numbers appear timeless. But logic does seem to say that such numbers are impossible. When we first think of the origin of things, we might think of things that could have been there forever, like numbers. But logic seems to say that there was originally stuff, not things; perhaps mental stuff, perhaps a God that is not exactly one thing. There would have been some possibility of things, and more arithmetic the more that God thought about that possibility.
      I should add a note about what sort of God is being shown to exist. The proof does not show that God could not have created a four-dimensional world in a Creative act above and beyond that temporal dimension. So this God might be what we call "timeless," and might know all about the future; or not. And either way, this God could always have known all of our textbook mathematics, if only because that is essentially axiomatic.