This article provides relevant context regarding the history and evolution of Wittgenstein's later thought. The SEP's article on private language is also recommended reading.

In my opinion, it only makes sense to discuss Wittgenstein's remarks when they situated in the context of the traditions of both analytic philosophy and phenomenology.

In my opinion, yes, on my understanding that it is linguistic convention which ultimately decides whether a sentence is true or false (for on any physical understanding of verbal behaviour, every assertion can be understood to be a true representation of it's physical causes, and therefore true).

Every person has their own linguistic convention and associated agenda, and conventions come into either conflict or cooperation for political reasons. Discussions and debates which on the surface look like passive disputes over the objective nature of shared truth, are ultimately analysable in terms of the resolution of socio-political objectives. But i don't see this as a nihilistic conclusion and more like an alternative view of philosophy.

Recall that the later Wittgenstein was negatively reappraising the phenomenalist doctrine of logical atomism that he, Russell and Mach previously assumed, where names are interpreted as stand-ins for sense data as suggested by the picture theory of meaning. But this solipsistic doctrine implies a fixed and idiosyncratic relationship between word meanings and the perceptions or mental states of a solitary speaker of the language, which in turn implies that the public meaning of such names in a community of speakers is synonymous to the use of indexicals like this, him, here, it, with names only communicating raw presence among speakers without a shareable accompanying description of what is perceived. Such a conception of names essentially ignores context, and in particular the (overwhelmingly complicated) inferential semantics that constitutes the descriptive function of names, both in the case of public communication and in the case of private introspection. As Wittgenstein illustrates, the actual usage of words , both in public and in private, ultimately defies any purported private or public definitions, except in the most trivial and useless cases. As with scientific and mathematics terminology, the definition of a natural language is forever playing catch-up after the facts.

The actual referents of a belief are it's immediate physical causes; so whenever a speaker asserts a so-called "false" belief, any alleged epistemic error exists solely in the minds of the listeners, due to their misidentification of the causes of the speaker's assertion.

How does a person experience dementia? presumably he finds himself learning about things that he has good reason to believe he has previously forgotten. But how does he classify an experience as being of something forgotten? Whatever the experiential criteria, perhaps an avid learner should consider dementia to be the ultimate learning experience.

I recall an interview in which Sam Harris (atheist, author, neuroscientist) claims that to believe nonexistence (I mean death) is unthinkable is, as he put it, "...for a lack of trying..." He explains: there are people in Paris, his choice of city, who don't know you exist; in other words, you don't exist as far as Parisians are concerned. That, according to Sam Harrris, is to give you a glimpse of what nonexistence is! — TheMadFool

There are people in Paris observing the Eiffel tower, who are not observing the computer monitor you are observing; in other words, your computer monitor doesn't exist as far as Parisians are concerned.

And so presumably according to Sam Harris, he has given you a glimpse as to what the non-existence of your monitor is.

What I mean is that one can look up the entry for the axiom of choice on nLab, without encountering a rant against ZFC. So I think you're the one adding that part, and not your fellow constructivists / category theorists / programmers or whatever direction you're coming from.

Indeed, nLab expresses choice as "every surjection splits," which they note means "every surjection has a right inverse," in set theory. This formulation is easily shown to be equivalent to the traditional statement of the axiom of choice. There is no distance between the category-theoretic and set-theoretic views of choice. — fishfry

Category theory is a useful meta-language for understanding precisely where the mathematical foundation proposed in the early 20th century goes wrong, as well as being helpful for relating alternative theories. CT is itself philosophically neutral in the sense that it only assumes the presence of identity arrows in a category, but places no other constraints on either the presence or absence of arrows, provided the laws of arrow composition and association are obeyed. Therefore disputes between intuitionists, formalists and platonists carry over into the language.

Like a mathematics department, nlab as an encyclopedia is obviously going to disseminate mathematics in a politically neutral fashion. Or perhaps i should have said, unlike a mathematics department. But political neutrality doesn't amount to reasonableness regarding which mathematics should be prioritised.

You lost me there. Absent AC there is a set that is infinite (not bijective with any natural number) yet Dedekind-finite (no proper subset is bijective with the entire set). I don't know what you mean here. — fishfry

I'm talking about stream objects in computer science, or equivalently the isomorphism
S <----> 1 x S in the Set category, where S is a stream object, 1 is the terminal object, i.e the singular set, and x is the Cartesian product. Unfolding the definition:

S <----> 1 x S <----> 1 x (1 x S) <----> 1 x (1 x (1 x S)) ....

Since each of the arrows is invertible, S clearly has, by definition, a surjection onto any finite set, which is what i meant by Kuratowski infiniteness.

On the other hand, recall that in category theory every element of a set S is an arrow of the form
1 --> S. However, these arrows haven't been specified in my above definition of S, and therefore the number of elements of S is currently zero, i.e. S is the empty set, which is another way of saying that S is a completely undefined set until the first observation is made.

Every time an observation is made, an arrow of the form 1--> S is introduced into the above category, and we can denote the current state of the stream by shifting from left to right in the above diagram. But at every moment of time, the arrow S --> S that is implicit in the the product S ---> 1 x S is a bijection, meaning that is S is forever dedekind-finite.

S cannot exist as an internal set of ZF because it isn't a well-founded set, although it can exist in the sense of an "external set" that is to say, inside ZF as part of a non-standard interpretation of an internal well-founded set. And it it cannot exist in any capacity inside ZFC.

All of which is tantamount to saying that ZF has only partial relevance to modern mathematics in terms of being an axiomatization of well-foundedness, whilst ZFC is completely and utterly useless, failing to axiomatize the most rudimentary notions of finite sets as used in the modern world.

I'm perfectly happy to stipulate so for purposes of discussion. After all, there are no infinite sets in physics, at least at the present time. So, what of it? The knight doesn't "really" move that way. Everybody knows that knights rescue damsels in distress, a decidedly sexist notion in our modern viewpoint. Therefore chess is misleading and unrepresentative nonsense. Nevertheless, millions of people enjoy playing the game. And millions more enjoy NOT playing the game. What I don't understand is standing on a soapbox railing against the game. If math is nonsense, do something else. Nobody's forcing you to do math, unless you're in school. And then your complaints are not really about math itself, but rather about math pedagogy. And I agree with you on that. When I'm in charge, a lot of state math curriculum boards are going straight to Gitmo. — fishfry

So are you agreeing that mathematical infinity has neither philosophical nor scientific relevance and that everyone knows this, or am i right to stand on a soap box and point out the idiocies and misunderstandings that ZFC seems to encourage?

I might point out, though, that assuming the negation of the axiom of choice has consequences every bit as counterintuitive as assuming choice. Without choice you have a vector space that has no basis. An infinite set that changes cardinality if you remove a single element. An infinite set that's Dedekind-finite. You lose the Hahn-Banach theorem, of vital interest in functional analysis, which is the mathematical framework for quantum mechanics. The axiom of choice is even involved in political science via the Arrow impossibility theorem. — fishfry

Obviously, a denial of AC doesn't amount to an assertion of ~AC, given that things are generally undecidable, but i see no counter-intuitive examples in what you present. In fact, many examples you raise should be constructively intuitive if we recall that construction can proceed either bottom-up from the assumptions of elements into equivalence classes, or vice versa, so an inability to locate a basis in a vector space using top-down construction seems reasonable.

As for the sciences, AC is meaningless and inapplicable when it comes to the propositional content. At best, AC serves a crude notation for referring to undefined sets of unbounded size, but ZFC is a terribly crude means of doing this, because it only recognises completely defined sets and completely undefined sets without any shade of grey in the middle as is required to represent potential infinity.

QM has also been reinterpreted in toposes and monoidal categories in which all non-constructive physics propositions have been removed, which demonstrates that non-constructive analysis is dying and going to be rapidly replaced by constructive analysis, to the consternation of inappropriately trained mathematicians who resent not knowing constructive analysis.

Besides, if you have a nation made up of states, can't you always choose a legislature? A legislature is a representative from each state. If there were infinitely many states, couldn't each state still choose a representative? The US Senate is formed by two applications of the axiom of choice. The House of Representatives is a choice set on the 435 Congressional districts. The axiom of choice is perfectly true intuitively. If you deny the axiom of choice, you are asserting that there's a political entity subdivided into states such that it's impossible to form a legislature. How would you justify that? It's patently false. If nothing else, each state could choose a representative by lot. — fishfry

Obviously, the axiom of choice isn't used in the finite case. In the infinite case, the sets of states needs to be declared as being Kuratowski infinite in order to say that the elements of the set are never completely defined, and so a forteriori the size of the set cannot be defined in terms of it's finite subsets.

Secondly, the set should be declared as Dedekind finite, in order to say that the set is an observable collection of elements and not a function (because only functions can be dedekind-infinite).

So, yes, you can choose as many representatives as you wish without implying a nonsensical completed collection of legislatures that are a proper subset of themselves, but formalisation of these sets isn't possible in ZFC, because AC and it's weaker cousin, the axiom of countable choice, forces equivalence of Kuratowski finiteness and Dedekind finiteness.

It upsets some people (Frega, Meta) that mathematical axioms don't necessarily "mean" anything or "refer" to anything. — fishfry

And it should do, for classical set theory and real analysis are misleading and unrepresentative nonsense, unless cut down to the computationally meaningful content. Students who are taught those subjects aren't normally given the proviso that every result appealing to the axiom of choice is nonsensical, question-begging and of use only to pure mathematicians and historians.

What seems clear to me is that if we do live out other lives, in order to do this, there has to be a source that maintains the continuity of the self, otherwise it's difficult to make sense of this idea. — Sam26

Why not just deny the possibility of eternal oblivion by denying the existence of a continuous self, even within a single lifetime? That way you circumvent the need for evidence of reincarnation, and avoid all of the scepticism that the begging of evidence entails.

In my understanding, he was pointing out that our inferences can neither be understood nor be given justification on a definitional basis on pain of infinite regress, a point first raised by Lewis Carroll , whom Wittgenstein was evidently inspired by and indebted to.

The impossibility of infinite analysis, coupled with the problem of theory under-determination, means that the inter-translation of rules and phenomena and even rules and rules is under-determined in both directions. Hence Tractatarian approaches to philosophy are profoundly misguided.

Precisely. the proposition ~R --> A isn't in contradiction with the proposition ~R -->C because both denote possibilities, as opposed to probabilities or propensities. To get the latter, a non-logical probability measure must be added.

Or alternatively, since precise probabilities are usually difficult and controversial to assign, one simply ranks ~R --> C above ~R --> A to indicate which they believe is the most likely.

Modus Ponens is a logical rule for the composition of possibilities but not probabilities, since all logical statements are relative to the truth of premises that are non-logical axioms. So it is perfectly acceptable to disbelieve the actuality of a conclusion of Modus Ponens, for non-logical reasons.

Logic specifies what can happen, but not what will happen. After all, if that weren't the case, then an axiomatic system such as Peano arithmetic wouldn't be a forest of proofs, but merely a single proof of one result consisting of a single chain of reasoning.

Needless to say, there is an (unfortunate) temptation among philosophers and mathematicians to mix the concepts of logic/possibility with statistics/probability by considering conditional-probabilities to be a generalised form of logical implication. This is generally disastrous, because possibilities are easier to state and justify than probabilities which are usually ill-defined and whose use is generally controversial.

Consider the fact that

A. Oceans aren't defined in terms of unions of droplets.

This means that atomically constructive definitions of oceans in terms of merging droplets together is irrelevant in terms of the logical characterisation of an ocean that assumes no physics. To mathematically define an ocean is to write it down instantaneously without constraining it's size.

B. Oceans are potentially infinite in terms of their number of droplets, but are not actually infinite.

This means that

1) An ocean is Dedekind-finite; there does not exist a constructable bijection between any number of droplets extracted from the ocean and a proper subset of those droplets.

2) An ocean is not specifiable a priori as a finite object in the sense that there is no a priori specifiable upper-bound on the number of droplets that can be extracted from it. In other words, an ocean, apriori, isn't equivalent to any a finite subset of droplets extracted from it. In mathematical parlance, oceans are therefore Kuratowski-infinite, like an infinite-loop in a computer program that isn't a priori equivalent to any finite number of loop iterations.

Together, 1 and 2 necessitate the rejection of the Axiom of Countable Choice, since that axiom forces all non-finite sets to be dedekind infinite.

Oceans are streams in a type-theoretical sense, which are lazily-evaluated lists

Ocean (0) = Ocean (no droplets so far extracted)
Ocean ( n) := [ droplet (n+1), Ocean (n+1) ] (n+1 droplets so far extracted)


Therefore we can say Ocean(0) > Ocean(1) > Ocean (2) .... without assigning a definite quantity to Ocean (0) and its predecessors, and without assuming that Ocean(i) is evaluated for all i, in the sense that only when we draw a droplet from ocean (i) does ocean (i) expand into [droplet(i+1), ocean (i +1) ].

And when the ocean eventually runs dry, our non-standard mathematical specification that is consciously aware of an a priori/ a posteriori distinction in mathematical meaning, isn't contradicted by reality, unlike in the case of classical set theory that in appealing to AC equivocates the a priori with the a posteriori.

I interpret you as asking: to what extent do acts of violence and destruction satisfy the motives of the terrorist?

This raises the question as to how the motives of terrorism, and violence in general, are determined, and the extent to which it is possible to determine motives through the analysis of language and behaviour.

For example, what were the motives of rampaging England fans after they lost to Italy? Is a Marxist analysis of English hooliganism warranted? or were they merely indulging in spontaneous and instinctual acts of self-gratification in the absence of a sufficient deterrent under the influence of alcohol? I'm inclined to believe both.

There might be something lurking in the notion of 'good reason' that has to do with degrees of good reason, which also relates to degrees of confidence in beliefs. And Pfhorrest broaches the matter of lack of certainty. I'm not inclined to it, but maybe a solution does lie in that direction. — TonesInDeepFreeze

In logic, either an arrow A -> B exists, or it does not. And so for logic there exists only possibility or non-possibility. On the other hand, probability measures over a set of propositions in a model of logic are chosen freely in accordance with external beliefs or experiments.

On the left side below are the axioms of OP's problem that specify every possible election outcome. On the right side is an example of a consistent set of degrees of confidence assigned to each possibility that coheres with every premise of the OP.

Andy or Carter --> Andy 0.25
Andy or Carter --> Carter 0.75

Reagan 0.80
Carter 0.15
Andy 0.05

As usual, Modus Ponens holds while saying nothing about the relative likelihood of possible winners.

Probability theory, which is currently the most fashionable calculus for representing and reasoning about beliefs and uncertainty, is only defined up to a measure over a sigma-algebra of sets denoting a collection of propositions. Unfortunately, practitioners of the theory don't normally consider this collection to be a model of any specific set of logical axioms, but rather as representing classes of observables, which means that modus ponens is formally absent from probability theory. Whenever an underlying logical system isn't specified in an application of probability theory (which is nearly all of the time), it is undetermined as to whether conditional probabilities or joint probabilities are the more fundamental epistemic principle.

Nevertheless, it is natural for Bayesian practitioners to assume some implicit underlying logic in an ad hoc fashion and to interpret modus ponens in terms of set intersections, in Venn diagram fashion. But as the example demonstrates, probabilities can behave non-intuitively with respect to modus ponens. Formally, Modus ponens speaks only of logical possibilities and not probabilities which are property of a model of a logic.

MP can be defined generally and abstractly as the composition of arrows in a category. In problems such as the above, the arrows denote conditional probabilities of the form P(B | A) between two propositions A and B , and premises denote arrows of the form 1 -> A, where 1 is a terminal object representing an "empty" premise.

The example also highlights a general problem: given a state of knowledge, is it consistent? and if so, how do you determine what the underlying arrows are?

In the previous example of the OP, the beliefs given are consistent. The arrows are the conditional probabilities of candidates winning given knowledge of the failure of one or more of the remaining candidates, and there is only one premise, namely that a republican wins.

If the principle of non-contradiction is regarded as being be logically necessary, then it cannot say anything apart from asserting a grammatical promise not to contradict oneself, in which case it is merely a normative linguistic principle rather than a empirically descriptive epistemic principle. On the other hand, if the principle is regarded as being empirically descriptive, then it must fallible, in which case it also cannot play a role in any epistemic foundation.

This also seems to be the case for any other suggested foundational principle: either it is regarded as being infallible, in which case it cannot rule out any conceivable possibility and hence is epistemically redundant, else it must be regarded as fallible and therefore not a foundational principle.

In the case of statistics or beliefs which involve probabilities,the standard non-probabilistic version of Modus Ponens is generally inapplicable,since there it isn't generally used as a constructive principle, and so it is neither fair nor surprising to point out the failure of MP in this situation . And yet statistical relations do obey a generalised version of Modus-Ponens with respect to conditional probabilities:

Take for instance, the following beliefs:

P (Reagan wins) = 0.80
P (Carter wins ) = 0.15
P (Andy wins ) = 0.05 (i.e. distant third republican)


P (Reagan or Andy) = 0.80 + 0.05 = 0.85 (i.e. the probability that a Republican wins)

P(Reagan | Reagan or Andy ) + P(Andy | Reagan or Andy) = 1 (i.e, as a logical tautology, Andy must win if Reagan doesn't, relative to the assumption that a republican wins)

But if Reagan doesn't win, then

P(Andy | Andy or Carter) = 0.05/ (0.05 + 0.15) = 0.25, (i.e. Carter remains favourite over Andy)

But notice that although this example contradicts (the misuse of) logical Modus Ponens, it doesn't contradict "probabilistic modus ponens" of the form P (B,A) = P( B | A) * P(A), which when summed over the values permitted for A recovers P(B).

In other words, if we take the conditional probabilities as being fundamental and follow this example in the bottom-up direction using this probabilistic modus-ponens, we recover the initial unconditional beliefs.

The axiom of inifinity is non-controversial, as it merely amounts to the inductive convention of calling a finite tree a "tree", a finite list a "list, a finite set a "set" etc. Nobody who talks about "lists", "trees" or "sets" in ordinary language implies a completed totality of such objects, and neither does the use of the axiom of infinity in a proof, because as we recall proofs by definition have finite derivations and use every axiom finitely.

The real numbers however, are nonsensical with respect to experimental physics and engineering, where their literal definition is at odds with respect to how the formalism is actually used. There, real numbers aren't used literally in the sense of referring to infinitely precise quanitities, but are used non-rigorously or "non-standardly" to refer to indefinite and imprecise quantities and taken together with noise and error terms. For this reason, in conjunction with the rapid ascent of automated theorem proving and functional programming that are based on type theory, the awkward, misleading and practically false language of real analysis can only die fast.

There are different formulations that may have equivalences, and there are complications throughout, but I know of no proof nor mention in the article you cited that shows the equivalence of AC with LEM in intuitionistic set theory. The SEP article does say "each of a number of intuitionistically invalid logical principles, including the law of excluded middle, is equivalent (in intuitionistic set theory) to a suitably weakened [italics in Bell's earlier article] version of the axiom of choice. Accordingly these logical principles may be viewed as choice principles." But the question was not that of various choice principles but of AC itself, and we have not been shown a proof that AC and LEM are equivalent in intuitionistic set theory. — TonesInDeepFreeze

yes, originally I was speaking roughly in relation to that article while making what i considered to be a tangential point in relation to the thread topic. As an axiom, LEM when interpreted in the Set category by the usual Tarskian approach, is an axiom of "finite choice" in the sense of asserting 'by divine fiat' the existence of a choice function for every relation into a finite set, i.e. that every finite set is 'choice '. Stronger choice principles additionally assert the existence of choice-sets that are the non-constructive infinite unions of the finite choice sets.

Observe that the meaning of choice principles are different in constructive logic than in classical logic, and recall that the controversies over LEM and AC concern only their implied non-constructive content.

Bear in mind

1) All of the non-constructive content of classical logic is discarded by jettisoning LEM.

2) The axiom of choice holds trivially as a tautology in sets constructed in higher-order constructive logic, because in this logic existence is synonymous with construction.

So one could even say that absence of LEM implies AC (or perhaps rather, that AC is an admissible tautology in absence of LEM).

But this statement isn't enlightening, because it conflates the difference in meaning that AC has in the two different systems, for AC holds trivially and non-controversially in constructive logic as a tautology, where it doesn't imply anything above and beyond construction.

In the constructive sense, i think it is fair to say that LEM implies AC, when speaking of AC not in the sense of an isolated axiom, but in the commonly used informal vernacular when speaking of choice principles in their structural and implicational senses

"And of course, we know that LEM does not imply AC, since we know that ZF is consistent with ¬AC while LEM holds." (MathStackExchange) :chin: — jgill

Sorry for the confusion. Yes that is true for ZF, since it is built upon classical logic. In set theory, controversial instances of the excluded middle are the result of both the underlying logic if it is classical as well as the set theoretic axioms of choice and regularity.

What i had in mind wasn't ZF, but intuitionistic set theory, in which choice principles and LEM are approximately equivalent as documented in the SEP article on the axiom of choice.

https://plato.stanford.edu/entries/axiom-choice/

News to me. You claim that being a Platonist ixs equivalent to believing in the axiom of choice? I'd take those two things to be totally independent of one another. You could be a Platonist or not, and pro-choice or not. I don't see the connection. — fishfry

The connection is the fact that the axiom of choice is equivalent to the law of excluded middle, which for infinite objects dissociates truth from derivation. This in itself wouldn't imply platonism if it wasn't for the fact that most proponents of classical logic and ZFC make no attempt to justify the formalisms pragmatically with respect to real world application.

Yes, I'm already aware of all of that, and was only speaking approximately on set theory. My point was only attacking the idea that quantity is reducible to ordering.

Demanding that the notion of quantity is synonymous with the notion of order is misguided, for a set is normally specified as a collection of things which satisfy a given predicate, and the "quantity" of such things usually makes no reference to a constructive ordering of the elements concerned but merely to the existence of other sets for which there exists a proveable bijection to the present set, a bijection that can merely involve a bi-directional translation of any given element of a set into another.

Ironically, it is the the platonists who insist that every set must be "well-ordered" which is an assumption equivalent to the axiom of choice. But for those who deny the axiom of choice, it is nevertheless meaningful to compare the "sizes" of different sets even if the determined sizes are not synonymous to counting elements.

Then there is the little matter of potential infinity. Mathematically, it might well be the case that the number of grains of sand in a heap is neither finite nor actually infinite, but indefinitely large. To argue differently is to argue the religion of physics rather than maths.

Suppose that a heap of sand is indefinitely large, in that every time a grain of sand is extracted from the heap it might be possible to remove from the heap yet another grain of sand. Even though the heap of sand is indefinitely large, it is nevertheless meaningful to speak of the original heap of sand as being larger than the heap with a grain of sand removed, and yet in this case it is only possible to count the grains removed from the heap.

Well, yes; if you have historical information then by that very fact you have a distinction between past and present... not at all sure what "ontological" is doing there, since the sentence works better without it. — Banno

Are the tenses of past, present and future reflective of distinct physical relations or substances, as the block universe advocates suggest?

According to the block universe in which the past, present and future are ontologically distinct, how is historical information even possible? For this view seems to imply that appearances in a given frame of reference at time t can speak only of what exists at time t. In which case, how can such appearances, whether taken individually or collectively, obtain historical significance?

How can the study of physics, which begs the ability to observe history, whether directly or indirectly, be even justified in relation to this block universe understanding, which seems to tacitly insist that all "historical evidence" can speak only of it's moment of existence?

Perhaps one could appeal to the existence of some form of information preserving causality, by which the present always "contains" the past, but that would imply physics to be mere religion, given that any supposed experimental confirmation of such a theory would be question begging. Plus it flies in the face of the second law of thermodynamics, which permits different potential histories of the universe to arrive at the same state in the future.

In the block universe there remains a distinction between how things are at one time and how things are at another. — Banno

Yes, but the same could be said of a diary. The fundamental question is, does the existence of historical information necessitate an ontological distinction between past and future? or do we merely record information in a linear fashion for convenience?

Consider your hard-disk. If you wipe your hard disk, then as far as your hard-drive is concerned the information that you had previously stored on your hard-disk not only does not exist, but it never existed.

The meaning of "the information that was on your hard-drive" only makes sense as a reference to information that continues to persist in another medium. But if the universe is a closed and bounded system, then the history of the universe doesn't have an external back-up. In which case, the block universe is objectively false and is merely a diary. For any change to the present state of the universe necessarily entails the deletion of historical information, meaning that history isn't static, time isn't a line from past to future and causality doesn't have a direction.

Another way of putting it is in terms of Lockean primary versus secondary qualities; Traditionally, the discipline of Physics charts only the primary qualities of objects, events and processes i.e. their mathematical interrelations, where the relationship of their primary qualities to their secondary qualities (i.e. qualia) is ignored and undetermined. The reason why the secondary qualities are classically ignored by physics is as a consequence of traditional physics treating it's subject matter to be independent of any particular observer, which is itself due partly to convenience and simplification, and due partly as a consequence of the objective of physics to model the causal relationships that hold between action and consequence irrespective of the contextual nuances and discrepancies of any given observer.

Strictly speaking, the propositions of physics are senseless, like an unexecuted computer program, until as and when the propositions are used by an agent and thereby become grounded in the agent's perceptual apparatus in a bespoke fashion, at which point Locke's secondary qualities become temporarily welded to the physical concepts.

Classical physical concepts are therefore by design irreducible to mental concepts; something has been a central feature of physics rather than a bug, at least up until the discovery of special relativity and quantum mechanics, both of which show that even the Lockean primary qualities of objects are relative to perspective.

Physicalism is the idea that the meaning of language is grounded in third person testimony and the results of unperformed experiments, i.e. counterfactuals. For if the meaning of language was considered to be grounded in first-person observations and the results of actually performed experiments, then the words "mass", "electromagnetic force", "neuron" and so on would reduce in a literal sense to the lived experience of the first-person, making physicalism ontologically reducible to mentalism.

In contrast to Darwinian life, transhuman life will seem self-evidently wonderful by its very nature.[/quote]

Is it rational to seek to eliminate death in the absence of any proof that life is better than death?
— Foghorn
But the problem, to quote Wittgenstein, is that "Death is not an event in life". Even if we share a Benatarian pessimism about the human predicament, we should have compassion for aging humans tormented by increasing decrepitude and their own mortality – and the loss of loved ones. Defeating the biology of aging is morally imperative.
In contrast to Darwinian life, transhuman life will seem self-evidently wonderful by its very nature. — David Pearce

"6.4311 Death is not an event in life: we do not live to experience death. If we take eternity to mean not infinite temporal duration but timelessness, then eternal life belongs to those who live in the present. Our life has no end in just the way in which our visual field has no limits."

Wittgenstein's quote indicates the logical inexpressibility of death as 'eternal oblivion' from the perspective of Tractatarian phenomenalism, which as a maximally empiricist theory of meaning is unavoidably both solipsistic and presentist. For such doctrines, all propositions about change, including so-called 'temporal passage', reduce to observational change relative to a present that only exists in the sense of a logical construct. The quote therefore doesn't appear relevant to arguments for defeating biological ageing, and if anything appears to undermine it.

As the quote indicates, presentists have no motivation to biologically preserve their own life for the purpose of avoiding eternal oblivion, given that they understand eternal oblivion to be nonsense. For the presentist, the present already is their immortality, implying that there isn't a moral imperative to prevent ageing. At most transhumanism offers the presentist a potential happiness-gradient following strategy for seeking a 'local optima' of happiness relative to their current circumstances. A presentist with an appetite for risk however, could rationally decide to abandon happiness gradient following and instead resort to nature's evolutionary search strategy, by committing suicide and hoping for a favourable rebirth, depending on his beliefs in karma.

The most charitably I can put it is this: the afterlifer is after something so radically different from life that it would simply have nothing to do with what we understand as life. It would be something wholly different that one could not even call it an afterlife. But what, exactly, would that be? Once the afterlife becomes unmoored from anything recognizable as life, then what conceptual bearings do we have to even talk of it? And here, the concept needs to be defined, long, long, long before any search for 'evidence' would even be remotely contemplated. — StreetlightX

But nobody agrees, or even can agree in principle, as to what life "means", since everyone's use of a proper name contradicts with each other. Society's use of proper names is physically and psychologically indescribable in terms of closed type-token relations, for each and every person uses the same proper name differently and in an off-the-cuff bespoke fashion that does not conform to any a priori definition of "personhood". The concept of "another mind" is essentially a perspectival, dynamic and open relation, whereby to imagine, to remember or even to recognise a physically present person is in some sense to construct that very person.

Consider a funeral gathering. It is remarkable how the mourners focus almost exclusively upon the sense of the person remembered, and how they pay so little attention to the physical referent of their mourning that lies in the coffin. And yet according to any public truth criteria of type-token physicalism that insists upon making a hard subject-object distinction, the mourners have nothing to be upset about, for only the physical referent of a proper-name objectively matters; the proper-name the mourners associate with their grief is either meaningless due to it referring to nothing, or it refers to what is in the coffin. Either way, the mourners feelings and personal memories are irrelevant to the ontological status of living or dead persons, and their personal experiences never come into contact with other minds.

I mean it though - the notion of an afterlife simply has no conceptual coherence. After-life = life beyond death. This is no different to a square circle. The woo peddlers reckon they get get around this by cleaving life into two such that there is bodily life on the one hand and then - depending on who you ask because there is no precision here at all - mental, spiritual, conscious or soul-life. But no one has any idea what this last kind of 'life' is, or exactly how 'life' and any of these categories are meant to be conceptually articulated. Or how the 'life' that qualifies any of these latter things has anything in common with the 'life' of the body. It's complete wordplay. A grammar mistake that, because it is so obviously incoherent to anyone with a basic grasp of english ("dead life that is alive"), must cover it up by making internal distinctions that have no purport at all, and fall apart at the slightest prodding because held together by nothing than pseudo-grammatical glue.

One doesn't need to 'argue' that square-circles don't exist: anyone who thinks they do disqualifies themselves as a speaker of english. So too peddlers of 'the afterlife'. — StreetlightX

That's true but it somewhat misses the point, given the flexibility of one's choice of grammar.

Chemists has no problem with the statement "Gold was destroyed on Earth, but later discovered in Alpha Centauri" - in spite of absence of information transfer.

Why are natural kinds such as gold and operating systems entitled to "after lives" , but not persons?

Consider the fact that a person isn't rigidly defineable as a type of object, due to an absence of essential criteria.

Why must Elvis Presley be treated as a rigidly designating proper name as opposed to a universal?

Isn't it purely down to the qualities of his impersonators singing and the legal politics of his estate?

o. But 'failure of imagination' is not itself an argument against even ludicrous, evidence-free ideas like "after lives" or "past lives". — 180 Proof

Supposing that one is an atomist to the point of being a mereological nihlist. Then isn't even the idea of a "living person" also evidence-free?

None. The question is metaphysical and therefore doesn't really concern evidence, for any answer to the scientific question "is there an after-life" whether "yes", "no", "maybe" or "mu" (meaning the question is nonsense) is tautologically decided.

For the scientific question to make sense, the concepts of "Persons", "lives" and "After-lives" must first be given definitions in terms of physically contingent types and/or natural kinds. At which point scientific evidence becomes relevant in so far as deciding whether a given "person" is now in the "after-life" state relative to the assumed ontology, which begs the entire metaphysical question.

I'll plead ignorance about this point, I don't know enough physics to comment on that.

But I guess my point is that the notion of “cause” may not be applicable to the total, as Russell pointed out in his famous debate with Copleston.

If we see the universe as a “set” or “collection/bundle of events”, then there may be no sense in asking what its cause is, just as there is no sense in asking what the cause of “the set of all ideas” is, in the same sense as we would ask what the cause of a rock, or of lightning, is.

But then again, Russell did also say that matter could also be seen as a way of grouping events into bundles, so maybe there is a sense in asking for the cause of sets after all. — Amalac

Right. As you point out, a notion of causality cannot play a role with respect to any data-set that is regarded as complete and self-contained. This creates a conflict within realism, for realists tend to simultaneously assert i) the transcendental reality of causality, ii) the transcendental existence of a completed universe whether finite or actually infinite, and iii) that counterfactual propositions have a definite truth value independent of actual measurements and observations.

By contrast, if the reality of an inter-subjectively complete universe is denied, then causality can not only retain it's useful meaning as referring to the potential outcomes of an intervention relative to an agent's perspective, but also it's ontological status to a limited extent, albeit not necessarily as a linear ordering of events from "past" to "future". Bayesian networks come to mind here.

By asymmetric causality, I am referring to either the belief or definition of causality such that causes come before their effects. This is a physically problematic assumption due to the fact that the microphysical laws are temporally symmetric.

mean, the past is either finite or it's infinite, right? What is meant by “potentially infinite” then? — Amalac

The realist interpretation of potential infinity is that it is epistemic ignorance of the value of a bounded variable. For the realist an unobserved variable has a definite value irrespective of it's measurement or observation . Hence for the realist, the value of a variable is either actually infinite or it is finite, with no third alternative.

Likewise, the constructive interpretation of potential infinity also refers to a bounded variable whose value if measured, is necessarily finite. The difference is, it doesn't assert the existence of any value until as and when the value is constructed. In computer programming terms, a potentially infinite natural number in this sense refers to a natural number variable that is lazily evaluated . Only upon evaluation, does the variable possess a definite (and finite) value.

The logic of a potentially infinite past in this constructive sense is superficially demonstrated in the video games genre known as "roguelikes", where a player assumes the role of an adventurer who explores a randomly generated dungeon that is generated on the fly in response to the player's actions.

The existence of the games are effectively a demonstration of the coherence of retro-causation that is conditioned upon the players present choices. Of course, a realist will be quick to point out that the implementation of such games demonstrates nothing of the sort, being as it is an ordered sequence of instructions with a beginning and end. The deficiency of the realist interpretation of the game must therefore be argued by other means, such as by the Quantum Mechanical refutation of local causation + counterfactual definiteness + no conspiracy.

In the current context regarding the truth of past-contingent propositions , a constructive interpretation of history is that a past cause of an event does not exist over and above the construction of presently existing historical information. For example, if the present state of the universe is compatible with Jack the Ripper having any number of historical identities, then according to historical constructivism Jack the Ripper did not exist and does not exist until as and when his/her identity is constructable from historical information. And because historical evidence is rarely conclusive, the constructivist is forced to reject the assignment of a definite truth value to most, if not all, past-contingent propositions.

The idea of an actually infinite past in the extensional sense of actual infinity is incompatible with the beloved premise of asymmetric causality running from past to future. In order to accept the premise of an actually infinite past, one must both theoretically reverse the direction of causality and somehow square that against physics and intuition, and in addition posit a finite future - a situation that is at least as problematic as the original picture. Or else one must entirely reject the notion of causality altogether - with the presumable consequence that having abandoned the doctrine of causality one must accept that one can no longer construct a theoretical or experimental argument for or against one's position.

In physics , the notion of actual temporal infinity is metaphysical in the literal sense of meta-physics, i.e it is a proposition that cannot be falsified, verified or even weakly evaluated through experiments.

However, there cannot be any empirical evidence on the basis of the observable universe to posit a past of any particular length. Therefore, the idea of a potentially infinite past is both perfectly consistent and the least assuming position to adopt. This position is adopted by presentists, who view the past and future as logical constructs that are reducible to sense-data. It's also compatible with quantum mechanics, due to the fact that QM has perpsectivalist retrocausal interpretations.

According to Oxfam in 2020, the world’s 2,153 billionaires have more wealth than 4.6 billion people, i.e. 60 percent of the world's population.

According to Statista, the wealth of US billionnaires grew by a trillion dollars since the start of the pandemic.

According to inequality.org, "US Billionaire wealth is twice the amount of wealth held by the bottom 50 percent of US households combined, roughly 160 million people."

According to americansfortaxfairness.org, "From 2010 to March 2020, more U.S. billionaires derived their wealth from finance and investments than any other industry. The financial sector boasted 104 billionaires in 2010 -- ten years later the number had grown to 160."

UBI amounts to a forced redistribution of capital from this tiny minority to everyone else. Correct me if i'm wrong, but I suspect that there aren't any billionnaires participating in this forum thread, so I am somewhat confused by the personal anxieties in this thread concerning the idea of UBI.