If you disagree on logic's relation to math, then start with what you think are the logical tools of Gödel's theorem — Gregory
Gödel noted that statements within a system can be represented by natural numbers. The significance of this was that properties of statements – such as their truth and falsehood – would be equivalent to determining whether their Gödel numbers had certain properties. The numbers involved might be very long indeed (in terms of number of digits), but this is not a barrier; all that matters is that we can show such numbers can be constructed.
In simple terms, we devise a method by which every formula or statement that can be formulated in our system gets a unique number, in such a way that we can mechanically convert back and forth between formulas and Gödel numbers. Clearly there are many ways this can be done. Given any statement, the number it is converted to is known as its Gödel number. — Wikipedia (Gödel numbering)
The Gödel sentence is designed to refer, indirectly, to itself. The sentence states that, when a particular sequence of steps is used to construct another sentence, that constructed sentence will not be provable in F. However, the sequence of steps is such that the constructed sentence turns out to be GF itself. In this way, the Gödel sentence GF indirectly states its own unprovability within F.
To prove the first incompleteness theorem, Gödel demonstrated that the notion of provability within a system could be expressed purely in terms of arithmetical functions that operate on Gödel numbers of sentences of the system. Therefore, the system, which can prove certain facts about numbers, can also indirectly prove facts about its own statements, provided that it is effectively generated. Questions about the provability of statements within the system are represented as questions about the arithmetical properties of numbers themselves, which would be decidable by the system if it were complete.
Thus, although the Gödel sentence refers indirectly to sentences of the system F, when read as an arithmetical statement the Gödel sentence directly refers only to natural numbers. It asserts that no natural number has a particular property, where that property is given by a primitive recursive relation. As such, the Gödel sentence can be written in the language of arithmetic with a simple syntactic form(...) — Wikipedia (Gödel incompleteness theorems)
I told you what I thought of it. It does not mean anything mathematically because it refers back on itself, a move of logic, not math. — Gregory
You can modify its form; some forms of modification are valid and some are not. I once had a form suggested to me which was not valid, namely the question whether the barber shaves himself or not. You can define the barber as "one who shaves all those, and those only, who do not shave themselves". The question is, does the barber shave himself? In this form the contradiction is not very difficult to solve. But in our previous form I think it is clear that you can only get around it by observing that the whole question whether a class is or is not a member of itself is nonsense, i.e. that no class either is or is not a member of itself, and that it is not even true to say that, because the whole form of (the?) words is just noise without meaning. — Russell
That's the part I believe everyone has overlooked. I will try and show this clearly:
x, y and z, are sets that are not members of themselves. I am trying to form a set of these three sets that are not members of themselves. — Philosopher19
If x, y, and z are sets that are members of themselves, and I form a set of these three sets, to represent this, I can write something like: p = {x, y, z}. I cannot write x = {x, y, z}. — Philosopher19
That a professor of mathematics (Frege) got tripped up by this shows how poorly thought out his program was — Gregory
When Bertrand Russell told Gottlieb Frege about the 'barber paradox' it had a momentous impact on Frege's whole life work. — Wayfarer
You can modify its form; some forms of modification are valid and some are not. I once had a form suggested to me which was not valid, namely the question whether the barber shaves himself or not. You can define the barber as "one who shaves all those, and those only, who do not shave themselves". The question is, does the barber shave himself? In this form the contradiction is not very difficult to solve. But in our previous form I think it is clear that you can only get around it by observing that the whole question whether a class is or is not a member of itself is nonsense, i.e. that no class either is or is not a member of itself, and that it is not even true to say that, because the whole form of words is just noise without meaning. — Russell
Hume would also probably say that our expectations are coincidental, too. Tomorrow you may wake up and expect apples to taste like watermelons. — god must be atheist
Nature, by an absolute and uncontrollable necessity has determined us to judge as well as to breathe and feel; nor can we any more forbear viewing certain objects in a stronger and fuller light, upon account of their customary connexion with a present impression, than we can hinder ourselves from thinking as long as we are awake, or seeing the surrounding bodies, when we turn our eyes towards them in broad sunshine. Whoever has taken the pains to refute this total scepticism, has really disputed without an antagonist, and endeavoured by arguments to establish a faculty, which nature has antecedently implanted in the mind, and rendered unavoidable. My intention then in displaying so carefully the arguments of that fantastic sect, is only to make the reader sensible of the truth of my hypothesis, that all our reasonings concerning causes and effects are derived from nothing but custom; and that belief is more properly an act of the sensitive, than of the cogitative part of our natures.
This is not true, I don't think so. The law of habit is not a law of causation. — god must be atheist
That’s not what Russell is saying, he’s saying that my expectation that when I see an apple in the future, it will taste like how apples usually taste and not like roast beef, is explained by the fact that I have always expected apples to taste that way in the past whenever I see them.
Thus, although in the past the sight of an apple (cause) has been conjoined with expectation of a certain kind of taste (effect), that gives no justification for the claim that it will continue to be so conjoined in the future.
Basically, expectations also fall prey to the problem of induction. — Amalac
if we take Hume seriously we must say: Although in the past the sight of an apple has been conjoined with expectation of a certain kind of taste, there is no reason why it should continue to be so conjoined: perhaps the next time I see an apple I shall expect it to taste like roast beef. You may, at the moment, think this unlikely; but that is no reason for expecting that you will think it unlikely five minutes hence. If Hume's objective doctrine is right, we have no better reason for expectations in psychology than in the physical world. — Russell
If x, y, and z are sets that are members of themselves, and I form a set of these three sets, to represent this, I can write something like: p = {x, y, z}. I cannot write x = {x, y, z}. — Philosopher19
But the key part of my post is that you cannot have a set of all sets that are members of themselves because it will result in at least one set being a member of itself twice. This is the overlooked part of Russell's paradox. — Philosopher19
The past, however, is treated as something complete - done with so to speak - and thus, any talk of the past being an infinity immediately sets off alarm bells inside our heads. — TheMadFool
Yes, the expectation is not justified. — unenlightened
I do not wish, at the moment, to discuss induction, which is a large and difficult subject; for the moment, I am content to observe that, if the first half of Hume's doctrine is admitted, the rejection of induction makes all expectation as to the future irrational, even the expectation that we shall continue to feel expectations. I do not mean merely that our expectations may be mistaken; that, in any case, must be admitted. I mean that, taking even our firmest expectations, such as that the sun will rise
tomorrow, there is not a shadow of a reason for supposing them more likely to be verified than not. — Russell
Nature, by an absolute and uncontrollable necessity has determined us to judge as well as to breathe and feel; nor can we any more forbear viewing certain objects in a stronger and fuller light, upon account of their customary connexion with a present impression, than we can hinder ourselves from thinking as long as we are awake, or seeing the surrounding bodies, when we turn our eyes towards them in broad sunshine. Whoever has taken the pains to refute this total scepticism, has really disputed without an antagonist, and endeavoured by arguments to establish a faculty, which nature has antecedently implanted in the mind, and rendered unavoidable. My intention then in displaying so carefully the arguments of that fantastic sect, is only to make the reader sensible of the truth of my hypothesis, that all our reasonings concerning causes and effects are derived from nothing but custom; and that belief is more properly an act of the sensitive, than of the cogitative part of our natures.
Birds have a habit of singing in the morning. There may be a cause or many causes or none, but the singing is not caused by the habit of singing. — unenlightened
(...)the law of habit is itself a causal law.
Therefore if we take Hume seriously we must say: Although in the past the sight of an apple has been conjoined with expectation of a certain kind of taste, there is no reason why it should continue to be so conjoined: perhaps the next time I see an apple I shall expect it to taste like roast beef. You may, at the moment, think this unlikely; but that is no reason for expecting that you will think it unlikely five minutes hence. If Hume's objective doctrine is right, we have no better reason for expectations in psychology than in the physical world.
I cannot write x = {x, y, z}. — Philosopher19
You cannot have a set of ALL sets that are not members of themselves because it will result in at least one set not being included in the set. In other words, x will have to be in x, but it can't. — Philosopher19
However, he did not venture a causal theory empirical knowledge; he took the above principles as more-or-less self-evident. It is fair to dissect and question Hume's empiricist principles. It is also fair to ask whether those principles are more foundational than our causal intuitions. However, I don't think it is fair in this case to accuse him of illicitly helping himself to the very ideas that he questioned. That Hume imagined impressions being caused by their objects is a speculation. — SophistiCat
I doubt whether either he or his disciples were ever clearly aware of this problem as to impressions. Obviously, on his view, an "impression" would have to be defined by some intrinsic character distinguishing it from an "idea," since it could not be defined causally. He could not therefore argue that impressions give knowledge of things external to ourselves, as had been done by Locke, and, in a modified form, by Berkeley. He should, therefore, have believed himself shut up in a solipsistic world, and ignorant of everything except his own mental states and their relations. — Russell
Empiricism and idealism alike are faced with a problem to which, so far, philosophy has found no satisfactory solution. This is the problem of showing how we have knowledge of other things than ourself and the operations of our own mind. Locke considers this problem, but what he says is very obviously unsatisfactory. In one place we are told: "Since the mind, in all its thoughts and reasonings, hath no other immediate object but its own ideas, which it alone does or can contemplate, it is evident that our knowledge is only conversant about them." And again: "Knowledge is the perception of the agreement or disagreement of two ideas." From this it would seem to follow immediately that we cannot know of the existence of other people, or of the physical world, for these, if they exist, are not merely ideas in any mind. Each one of us, accordingly, must, so far as knowledge is concerned, be shut up in himself, and cut off from all contact with the outer world.
This, however, is a paradox, and Locke will have nothing to do with paradoxes. Accordingly, in another chapter, he sets forth a different theory, quite inconsistent with the earlier one. We have, he tells us, three kinds of knowledge of real existence. Our knowledge of our own existence is intuitive, our knowledge of God's existence is demonstrative, and our knowledge of things present to sense is sensitive (Book IV, Ch. III).
In the next chapter, he becomes more or less aware of the inconsistency. He suggests that some one might say: "If knowledge consists in agreement of ideas, the enthusiast and the sober man are on a level." He replies: "Not so where ideas agree with things." He proceeds to argue that all simple ideas must agree with things, since "the mind, as has been showed, can by no means make to itself" any simple ideas, these being all "the product of things operating on the mind in a natural way." And as regards complex ideas of substances, "all our complex ideas of them must be such, and such only, as are made up of such simple ones as have been discovered to coexist in nature."
Again, we can have no knowledge except (1) by intuition, (2) by reason, examining the agreement or disagreement of two ideas, (3) "by sensation, perceiving the existence of particular things"
(Book IV, Ch. III, Sec. 2).
In all this, Locke assumes it known that certain mental occurrences, which he calls sensations, have causes outside themselves, and that these causes, at least to some extent and in certain respects, resemble the sensations which are their effects. But how, consistently with the principles of empiricism, is this to be known? We experience the sensations, but not their causes; our experience will be exactly the same if our sensations arise spontaneously. The belief that sensations have causes, and still more the belief that they resemble their causes, is one which, if maintained, must be maintained on grounds wholly independent of experience. The view that "knowledge is the perception of the agreement or disagreement of two ideas" is the one that Locke is entitled to, and his escape from the paradoxes that it entails is effected by means of an inconsistency so gross that only his resolute adherence to common sense could have made him blind to it.
This difficulty has troubled empiricism down to the present day. Hume got rid of it by dropping the assumption that sensations have external causes, but even he retained this assumption whenever he forgot his own principles, which was very often. His fundamental maxim, "no idea without an antecedent impression," which he takes over from Locke, is only plausible so long as we think of impressions as having outside causes, which the very word "impression" irresistibly suggests. And at the moments when Hume achieves some degree of consistency he is wildly paradoxical.
Here is why I think Hume's account of causality is self-refuting: it presupposes a causal relation between perception and belief. Because, according to Hume, we perceive certain events constantly conjoined, we believe that they are causally related. The perception causes the belief. Hume even admits that belief in causality is very convenient, since it helps us make sense of experience. But this also entails a causal relation, since if the belief in causality helps us make sense of experience, then the belief causes us to make better sense of experience. — Noisy Calf
The fact is that, where psychology is concerned, Hume allows himself to believe in causation in a sense which, in general, he condemns. Let us take an illustration. I see an apple, and expect that, if I eat it, I shall experience a certain kind of taste. According to Hume, there is no reason why I should experience this kind of taste: the law of habit explains the existence of my expectation, but does not justify it. But the law of habit is itself a causal law.
Therefore if we take Hume seriously we must say: Although in the past the sight of an apple has been conjoined with expectation of a certain kind of taste, there is no reason why it should continue to be so conjoined: perhaps the next time I see an apple I shall expect it to taste like roast beef. You may, at the moment, think this unlikely; but that is no reason for expecting that you will think it unlikely five minutes hence. If Hume's objective doctrine is right, we have no better reason for expectations in psychology than in the physical world.
(...)
Hume shrank from nothing in pursuit of theoretical consistency, but felt no impulse to make his practice conform to his theory. Hume denied the Self, and threw doubt on induction and causation. He accepted Berkeley's abolition of matter, but not the substitute that Berkeley offered in the form of God's ideas. It is true that, like Locke, he admitted no simple idea without an
antecedent impression, and no doubt he imagined an "impression" as a state of mind directly caused by something external to the mind. But he could not admit this as a definition of "impression," since he questioned the notion of "cause." I doubt whether either he or his disciples were ever clearly aware of this problem as to impressions. Obviously, on his view, an "impression" would have to be defined by some intrinsic character distinguishing it from an "idea," since it could not be defined causally. He could not therefore argue that impressions give knowledge of things external to ourselves, as had been done by Locke, and, in a modified form, by Berkeley. He should, therefore, have believed himself shut up in a solipsistic world, and ignorant of everything except his own mental states and their relations.
Spatial differentiation is perceivable/sensible, yes? (hm not sure "sensible" is the right word here) — jorndoe
I actually said, if you would kindly check, that an infinite number of years passed, not an infinite amount of time. — god must be atheist
"A year passed after a point in time that marked the end of the previous year, in an infinite series." — god must be atheist
If you need to know how I defined "passed", which is a commonly used English term or word — god must be atheist
Elapsed time is simply the amount of time that passes from the beginning of an event to its end.
(...) In simplest terms, elapsed time is how much time goes by from one time (say 3:35pm) to another (6:20pm).
I did not say "It happened since never." — god must be atheist
I answered your question. — god must be atheist
And then it's clear that there are an infinite number of years that have passed already to the present day. — god must be atheist
I think we are being invited to consider this project to be logically incoherent; as opposed to merely practically impossible, like reciting the digits of pi forwards. Forwards, you'll never finish. Backwards, you will never have begun. — Cuthbert
Do we have valid reasons to justify such differential treatment of space and time? Why is time (thought to be) in "motion" and space (thought to be) is "motionless"? — TheMadFool
Witnessing indicates observation. To witness an object from outside its limits merely indicates observing the object’s spatial boundaries. — Mww
Assuming the absolute validity of the principle, the only reconciliation is simultaneity, in which time is no longer presupposed, yet for which account is given. — Mww
There is no present. Questions predicated on impossibilities are irrational. — Mww
How is that not contradictory? — Philosopher19
Does a Sherlock Holmes at least exist as a character (perhaps in a story)? Yes. — Philosopher19
If we take the absolute approach (no degrees), then no, you don't have existence. — Philosopher19
Descartes' I think therefore I am established that something indubitably exists. — Philosopher19
But only God cannot be any more complete/perfect as a being. — Philosopher19
No, you are now equivocating “is” as a copula and “is” as a synonym of “exists”. — Amalac
When you assume "...the universe was infinite towards the past...", you shouldn't be asking "...since which moment down to the present did it pass? Since when to when did it pass?" because that question, whatever else it is, presupposes a beginning, a starting point, to time - the "which moment", the"when" in "when to when". — TheMadFool
To be an imaginary human, is to exist an imaginary human? — Philosopher19
To be a human on planet earth, it to exist as a human on planet earth? — Philosopher19
Do you agree that to be imperfect as a triangle, is to exist imperfectly as a triangle? — Philosopher19
Do you agree that to be imperfect as a being/existent, is to exist imperfectly as a being/existent? — Philosopher19
Note that you cannot say to be a square-circle, is to exist as a square-circle. Such a thing is impossible. Absurdities and contradictions exist, but what they describe (round squares) does not. By definition that which is contradictory is absurd or not true of existence. — Philosopher19
Perfection = that which is perfect. The perfect being. That which perfectly exists. — Philosopher19
You claim to have no problems with an infinite past but then you say you can't accept that "if the universe has an infinite past then an infinite amount of time must have passed". It doesn't add up. — TheMadFool
Do you think it's better to be in a truly perfect existence or not?
Do you think it's better to be God or not? — Philosopher19
B) Whatever's perfectly existing, is indubitably existing (just as whatever's perfectly triangular, is indubitably triangular). — Philosopher19
It is better to be the real God than to exist as just an illusion/image of God (the real God is better than all humans or image/imaginary/pretend gods). We are meaningfully/semantically aware that something perfectly/indubitably exists — Philosopher19
The most effective refutation of such kinds of ontological arguments that I know of is the one invented by Kant: existence is not a predicate, or if you prefer Frege: existence is a second order predicate.
If that is true, then it makes no sense to think of existence as a “quality which is better to have”:
Suppose I express my idea of a blue apple by painting a picture of five blue apples. I point my finger at it and say, "This represents five blue apples." If later I discover that blue apples really exist, I can still point to the same picture and say, "This represents five real blue apples." And if I can't discover the existence of the blue apples, I can point to the painting and say, "This represents five imaginary blue apples." In all three cases the picture is the same. The concept of five real apples does not contain one more apple than the concept of five possible apples. The idea of a unicorn will not get more horns just because unicorns exist in reality. In Kant's terminology, one does not add any new properties to a concept by expressing the belief that the concept corresponds to a real object external to one's mind.
— Martin Gardner
Here is a (short) explanation of Frege's criticism — Amalac
SO the question arrises as to how accurately it represents Kant's argument. — Banno
Suppose the world does not have a beginning in time. In this case, an eternity has elapsed until each given instant and, consequently, an infinite series of successive states of things in the world. Now, the infinity of a series consists in that it can never be finished by means of successive syntheses. Therefore, an infinite past cosmic series is impossible and, consequently, it is an indispensable condition of the existence of the world that it has had a beginning, which is the first point that we wanted to demonstrate. — Kant
First, if it works it does not show that the ontological argument for God does not work, it just establishes the devil's existence as well. — Bartricks
The no devil corollary is similar, but argues that a worse being would be one that does not exist in reality, so does not exist. The extreme no devil corollary advances on this, proposing that a worse being would be that which does not exist in the understanding, so such a being exists neither in reality nor in the understanding. Timothy Chambers argued that the devil corollary is more powerful than Gaunilo's challenge because it withstands the challenges that may defeat Gaunilo's parody. He also claimed that the no devil corollary is a strong challenge, as it "underwrites" the no devil corollary, which "threatens Anselm's argument at its very foundations".
— Wikipedia
But an omnipotent and omniscient being will also be omnibenevolent — Bartricks
The devil corollary proposes that a being than which nothing worse can be conceived exists in the understanding (sometimes the term lesser is used in place of worse). Using Anselm's logical form, the parody argues that if it exists in the understanding, a worse being would be one that exists in reality; thus, such a being exists. — Wikipedia
Everywhere, counterintuitive implications everywhere? Should we just make stuff up? Drop sufficient reason (in this case at least)? Are we back to square one? A non-infinite "edge-free" universe? — jorndoe
What lesson did Kant draw from these puzzling antinomies? He concluded that our ideas of space and time are inapplicable to the universe as a whole. We can, of course, apply the ideas of space and time to ordinary physical objects and physical events. But space and time themselves are not objects or events: they cannot even be observed, they are more elusive. They are a kind of framework for things and events, something like a box system, or a recording system, for observations. Space and time are not part of the empirical, real world of things and events, but are part of our mental equipment, of our apparatus to capture the world. The appropriate use that can be given to them is that of observation instruments: when observing any event we usually place it, immediately and intuitively, in an order of space and time. Thus, space and time can be considered as a frame of reference that is not based on experience, but is used intuitively in experience and is appropriately applicable to it. This is why we are inconvenienced when we misapply the ideas of space and time, and use them in a realm that transcends all possible experience, as we did in our two proofs on the universe as a whole. — Karl Popper