Comments

  • Infinite casual chains and the beginning of time?
    Do you understand the difference between "having the same value", and "being the same"?
    — Metaphysician Undercover

    Yes, that’s why I said that both sides of the equation are different expressions of the same value. What part do you disagree with?
    — Luke

    The different expressions represent different things with the same value... I don't really know what you would mean by "different expressions of the same value".
    — Metaphysician Undercover

    Do you understand what you mean by it (in your first sentence of the quote above)? Why do you think I mean anything different? You’re arguing against yourself here.
    — Luke

    Sorry Luke, I have no Idea what you're talking about here. I did not use "it", and you're not making clear what "it" refers to.
    Metaphysician Undercover

    If you can't even follow the discussion, then never mind.
  • Infinite casual chains and the beginning of time?
    The different expressions represent different things with the same value... I don't really know what you would mean by "different expressions of the same value".Metaphysician Undercover

    Do you understand what you mean by it (in your first sentence of the quote above)? Why do you think I mean anything different? You’re arguing against yourself here.

    So when it is said that "they have the same value", it is implied that they have the same value within a particular system of evaluation, the mathematical system.Metaphysician Undercover

    I thought we were all talking about “the mathematical system”?
  • Infinite casual chains and the beginning of time?
    You're arguing that both sides of an equation have equal (the same) value, but that they are different expressions of that value? Sounds reasonable.
    — Luke

    What are you talking about? How can you be so daft in your interpretation...

    Do you understand the difference between "having the same value", and "being the same"?
    Metaphysician Undercover

    Yes, that’s why I said that both sides of the equation are different expressions of the same value. What part do you disagree with?
  • Infinite casual chains and the beginning of time?
    mathematicians use "=" to indicate that two things have the same mathematical (quantitative) value, not to indicate that the things designated by the two sides of the equation are the same thing.Metaphysician Undercover

    You're arguing that both sides of an equation have equal (the same) value, but that they are different expressions of that value? Sounds reasonable.
  • Infinite casual chains and the beginning of time?
    My argument is that this use, to use "equal" and "the same" synonymously, is in violation of the law of identity, and therefore unsuitable for any system of logic.Metaphysician Undercover

    What does the use of these terms have to do with the law of identity?

    You seem to be saying that "equal" is a suitable term in relation to the law of identity, but "the same" is not. That is, you are attempting to prescribe the use of these terms to be non-synonymous. But why can't these terms be used synonymously in relation to the law of identity?
  • Infinite casual chains and the beginning of time?
    In other words, is there a difference between being equal and being the same.Metaphysician Undercover

    There can be a difference; it depends how the terms "equal" and "the same" are being used. But the terms "equal" and "the same" can also be used synonymously. Is this the basis of your dispute?
  • Infinite casual chains and the beginning of time?
    But are you ready to agree that since there is a "+" in "2+2",this phrase refers to a process?Metaphysician Undercover

    This is your problem, you are reading "2+2" as 4, instead of reading it as directions of how to get to 4. .Metaphysician Undercover

    So if you follow the directions and complete the process, then 2+2 = 4?
  • Natural and Existential Morality
    That's not making a different point. Me: "50% of the fruit is apples." You: "Actually, 100% of the apples are." ???Kenosha Kid

    Since the retraction of your OP statement that those with little to no empathy (again, what's the cutoff and how is it decided?) deserve their own moral frame of reference, I take issue with your remaining claim that the fundamental rule of hypocrisy applies only statistically. In response to my initial post on this matter, you compared such people as morally equivalent to chairs, buckets of water, and letter sequences. Do you also include those objects in your statistics?

    Edit: If the rule of hypocrisy is statistical, then you need to explain what counts or doesn’t count as being a moral agent. Is it having a level of 0% empathy or more than 0%? How is that cutoff level decided and how is that empathy level measured? In short, if it’s statistical, then I think you need to better justify the exclusion of some agents from having to follow the rule.
  • Natural and Existential Morality
    No, it's besides the point. This argument of yours is like responding "You're wrong, all bananas are curved" to the statement "Not all fruit is curved".Kenosha Kid

    Not at all. You said in the OP:

    Even the nearest to a fundamental rule -- do not be a hypocrite -- is not objective but statistical: there exist many for whom this is a practical impossibility because they lack empathy.Kenosha Kid

    The fundamental rule can apply only to moral agents. If psychopaths are excluded from being moral agents, then the fundamental rule cannot apply to them. Moral rules can only apply to moral agents. I don't see the relevance of statistics among moral agents.

    This argument of mine is like responding "You're wrong, this moral rule applies to all moral agents" to the statement "This moral rule doesn't apply to all agents (both moral and amoral)".
  • Natural and Existential Morality
    If I consider a population of 99 fully-functioning social humans and one psychopath, 99% of them are moral agents, not 100%. That is, if I, as a fully-functioning social human (says I!) were to attest a rule that one should behave reciprocally, knowing that 1% of the population cannot do this, I can only expect a maximum of 99% to follow that rule, not 100%.Kenosha Kid

    100% of moral agents should behave reciprocally. That's the point. That's why it's objective and not statistical.
  • Natural and Existential Morality
    If 99% of the population can practically follow a rule, the rule can hold statistically, not objectively. This is the point you are countering but I'm not seeing what you think the killer blow is.Kenosha Kid

    The "killer blow" is that you have excluded 1% of the population from consideration for being "qualitatively different": "Psychopaths are not outliers, they are qualitatively different." Or, as you put it earlier:

    If psychopaths have no emotional empathy, and no cognitive empathy reflex, their frame of reference cannot be considered moral.Kenosha Kid

    This means that 100% of the population under consideration are capable of practically follow the rule, making the rule categorically objective and not statistical. For them to act otherwise must be hypocritical, antisocial, non-altruistic, and thus objectively immoral.

    That is, as far as your OP is concerned, because the "statistical" reason was the only exception you provided for why the fundamental rule of hypocrisy is not objective.
  • Natural and Existential Morality
    Why do you believe that statistics is impossible with categorical data? I do statistics with categorical data all the time. My point was that one cannot consider a psychopath to be immoral but rather amoral since they mostly lack the practical possibility of engaging in reciprocal altruism.Kenosha Kid

    I never said that "statistics is impossible with categorical data". However, if it's categorical then it's not a matter of statistics or degree. What is the cutoff for being amoral instead of immoral/moral? What determines that value judgement? A definite dividing line between those categories is not something "empirically observed" in nature.

    Basic moral conceptions are ill-informed and often inaccurate approximations to sociobiological responses that we are otherwise unaware of.Kenosha Kid

    Really? Was there a general consensus that sociality and altruism were bad prior to these scientific insights?

    I do associate them: I do not equate them.Kenosha Kid

    You defined them as synonymous. Is that not equating them?
  • Natural and Existential Morality
    Not at all, the difference between social and antisocial is categorical.Kenosha Kid

    Then your assertion of the OP: "Even the nearest to a fundamental rule -- do not be a hypocrite -- is not objective but statistical" is false.

    The near-fundamental rule of 'do not be a hypocrite' is not statistical, but categorical: one is either social or antisocial. Yet your claim is that this rule is "not objective but statistical".

    No, I did not describe hypocrisy as a fundamental rule of naturalistic morality... if we from our post-agricultural, morality-obsessed vantage point wish to characterise how those drives and capacities work in conjunction with some constrained but otherwise arbitrary culture, those "fundamental rules" are how we might do it: i.e. they are the precursors of rational morality, not the foundations of socialisation.Kenosha Kid

    The "fundamental rule" (or near-fundamental rule) in question here is 'do not be a hypocrite' which you have defined or equated with being social or with not being antisocial. How is being social "not the foundations of socialisation"?
  • Natural and Existential Morality
    Mea culpa! It's a long OP. There will be errors, sorry.Kenosha Kid

    To which "error" are you referring? It's not just a typo; it appears to impact your argument that the fundamental rule of hypocrisy is statistical rather than objective.

    Okay, but why is hypocrisy so terrible?
    — Luke

    If you have no confidence that an altruistic deed will be reciprocated, there is no personal benefit in making them.
    Kenosha Kid

    So you define hypocrisy as failing to reciprocate altruism or as being antisocial? That's not a typical definition, to my knowledge, but okay.

    If your question is Why is hypocrisy objectively terrible?, then the question has no meaning. As I've explained to Pfhorrest, it is unreasonable to revert to an objectivist idea of morality when investigating a scientific naturalist idea of the same: the two are incompatible on that level.Kenosha Kid

    If you're making the claim that morality has a natural explanation via a bottom-up scientific approach, in which you describe hypocrisy as a "fundamental rule" (except for a statistical argument that you have since described as "oxymoronic"), then why is hypocrisy not objectively terrible?

    As you recently told me, nature justifies belief in an objective existence by "demonstrating herself to be accurately described, in part, by scientific models".
  • Natural and Existential Morality
    I did not mean to be dismissive. I am genuinely interested in what you mean by "false practice".

    Re: exoneration, if I were able to forgive myself for an act of killing someone, then I think I would have little trouble being able to forgive myself for an act of hypocrisy.
  • Natural and Existential Morality
    This is oxymoronic. If psychopaths have no emotional empathy, and no cognitive empathy reflex, their frame of reference cannot be considered moral.Kenosha Kid

    Agreed, but it it's your oxymoron, not mine. As you stated in the OP:

    Even the nearest to a fundamental rule -- do not be a hypocrite -- is not objective but statistical: there exist many for whom this is a practical impossibility because they lack empathy. They simply cannot equate the harm they do with the harm they'd feel if roles were reversed. Such people must be allowed their own moral frames of reference, because if you were in their shoes, that's what you should expect.Kenosha Kid

    This "statistical" argument is the only one you appear to offer for why the fundamental rule of hypocrisy is not objective. Do you now reject your statistical argument as oxymoronic? If so, then your fundamental rule of hypocrisy would appear to be objective...?

    "hypocrite" here is as defined in the OP.Kenosha Kid

    Okay, but why is hypocrisy so terrible?
  • Natural and Existential Morality
    If hypocrisy reduces to the intentional construction of false practicesMww

    What is a "false practice"? What is the "intentional construction" of them?

    Another way to look at it, is the reality of possible exoneration from a killing, as opposed to the reality of impossible exoneration for the negation of self-respect.Mww

    Exoneration by who?

    This is the separation of cultural anthropology from moral philosophy, the former says it is true we are not acculturated from a social perspectiveMww

    I did not mean to imply that we are not acculturated from a social perspective whatsoever; only that we are not acculturated to hold or accept a particular belief/attitude towards serial killers. Besides, I don't see any separation between cultural anthropology and moral philosophy in the OP.
  • Natural and Existential Morality
    There cannot be, then, a meaningful objective moral universe. Morality, viewed (correctly imo) in this bottom-up way, cannot have top-down rules because that is not what morality really is. Even the nearest to a fundamental rule -- do not be a hypocrite -- is not objective but statistical: there exist many for whom this is a practical impossibility because they lack empathy. They simply cannot equate the harm they do with the harm they'd feel if roles were reversed. Such people must be allowed their own moral frames of reference, because if you were in their shoes, that's what you should expect.Kenosha Kid

    Firstly, I get the sense that's not how morality works. We, as a social group, don't agree - or, at least, we aren't acculturated to accept/believe - that psychopathic serial killers should be allowed their own individual moral frame of reference. That would be dangerous to the rest of the social group. I therefore question this "statistical" argument and/or the relevance of differing levels of empathy.

    Secondly, why is being a hypocrite such a terrible thing? Is it worse than killing people?

    Thirdly, if the same moral truths are arrived at from either bottom-up or top-down approaches, then what's the difference?
  • Natural and Existential Morality
    That we know what we know about those biological drives comes from reason, so this is an assault purely on rationalism, not reason itself, which is pretty great actually, if over-credited.Kenosha Kid

    As I said to Pfhorrest, if anyone can justify the objective existence of moral truths in the same way that nature has justified belief in an objective existence, the OP is wrong, and I am stumped as to what the evidence in hand can possibly mean.Kenosha Kid

    How has nature justified belief in an objective existence? Was it via rationalism or reason itself?
  • Mary's Room
    If it is not knowledge, then Jackson's argument failsA Raybould

    Yes, I agree.
  • Mary's Room
    I think that most proponents of that view would say that she would be able to remember colors, compare colors, and even perform Hume's task of imagining an intermediate hue between two that she is seeing, before ever learning any names for them. It is mildly interesting to wonder if she would divide up the spectrum as we do (at which point, I must say that I have always regarded the distinction between indigo and violet as questionable!)A Raybould

    To add to my previous rushed response, even if we admit that one gains the ability to remember and compare colours, it is unclear how or whether this is a gain of knowledge of any sort. What knowledge-that or knowledge-how does one gain from this purely mental ability? How might one prove that they are able to remember or compare colours?
  • Natural and Existential Morality
    There are no longer single, small, homogeneous social groups for which our social drives were developed. We have a different kind of environment now. The idea of a social group persists in a more malleable way: the nuclear family, work colleagues, friends, social network, my church (I don't have one) or other community. Less so these days, we have communities centred around neighbourhoods. This is no longer one social group but many 'virtual' groups. We no longer inhabit them immediately and unavoidably, but dependently.Kenosha Kid

    I find it unclear what 'virtual' or 'malleable' are supposed to mean here. It seems like an effort to negate the multiplicity of social groups in favour of one global social group. The reason for my question was that it appears you are simply re-labelling good and bad behaviour as social and anti-social behaviour, which leaves open the question of what counts as social and anti-social behaviour. This question is probably somewhat easier to answer in the case of one global social group, but is more complex with multiple social groups. Evidence of multiple social groups with real effects for one group vs another is easily found in the actual groups that you mention above, or in relation to current issues such as the Black Lives Matter movement or recent events in Hong Kong. What is social or anti-social for one group may not be the same for another, especially when those groups are in conflict.
  • Mary's Room
    I prefer the Wittgensteinian view that colour samples have a function similar to (or equivalent to) that of grammatical rules. The ability to remember and know colours without names seems a little too close to a private language.
  • Heraclitus Weeps For Us, Democritus Laughs At Us
    This thread reminds me of my favourite quote:

    Tragedy is when I cut my finger. Comedy is when you fall into an open sewer and die. — Mel Brooks
  • Mary's Room
    I tend to favour the ability hypothesis mentioned in the Wikipedia article, which is that Mary gains knowledge-how rather than knowledge-that, namely, knowledge of how to use the word 'red'. However, I would add the proviso that Mary does not actually gain any knowledge (knowledge-how) at all until she learns that the colour she is seeing is called 'red', or in other words, until she learns how to connect the red sample with the word 'red'. This cannot be expected to be learned automatically.
  • Natural and Existential Morality
    The social group can no longer be regarded as family and neighbours. Families are generally distributed, and neighbours often unknown to us. Social groups are virtual and malleable: we work with one set of people, live with another set, socialise with another set, etc. These days, people are likely to have friends and relatives who live or come from a different country. There is no even vaguely-defined boundary you can draw around yourself and say: this is my social group. Your virtual social group encompasses the globe and is overwhelmingly diluted by strangers.Kenosha Kid

    Are you implying that there are no longer any social groups, or that individuals belong to too many social groups such that those groups no longer matter?
  • Metaphysics Defined
    If that were the case, then it would be impossible for the ideas to later be found to have value outside of metaphysics.
    — Luke

    I'm not sure that follows.
    Kenosha Kid

    Why not?

    If on my 18th birthday I am an adult, and that adult grew out of a child, does it follow a child is an adult?Kenosha Kid

    The child will later be (later become) an adult, just as some metaphysical ideas will later be (later become) valuable, as per your own examples. By analogy, your assertion is that the child will never be (never become) an adult, just as metaphysics is "all of the ideas that will never be found to have any value" (never become valuable).

    When Democritus formulated the atom theory, he was starting the ball rolling on science. I'm happy to agree that his was a metaphysical theory that had potential value, and that value underlies parts of physics and chemistry where it was put to good use. However the field of questions that Democritus was answering as broadly met by metaphysics do not inherit the value that scientists later found in atom theory, nor is it obvious that, had Democritus not formulated atom theory back then, science would be unaware of it, i.e. that Democritus' idea was even relevant. My point was simply that, because atom theory has value, its natural home is in the sciences: that's where it is valuable. As a purely metaphysical idea, it is not obviously more valuable than cosmic mind theory.Kenosha Kid

    Either Democritus' idea was once metaphysical and later became valuable and non-metaphysical, as with your other examples, thus contradicting your assertion that metaphysics is "all of the ideas that will never be found to have any value"; or else your examples are unrelated and irrelevant to this assertion.
  • Metaphysics Defined
    ... later found to have value outside of metaphysics, though.Kenosha Kid

    Yes, but the ideas were previously inside of metaphysics, according to your examples. Your assertion was that any ideas inside of metaphysics "will never be found to have any value". If that were the case, then it would be impossible for the ideas to later be found to have value outside of metaphysics.

    It is therefore incorrect to assert that metaphysics is "all of the ideas that will never be found to have any value".
  • Metaphysics Defined
    Therefore, metaphysics cannot be "all of the ideas that will never be found to have any value". — Luke

    Of course it can, if the moment it had value it ceases to be metaphysics.
    Kenosha Kid

    If something that was once part of metaphysics is later found to have value, then you cannot say that metaphysics is "all of the ideas that will never be found to have any value".

    "Later found to have value" != "will never be found to have any value".

    Per your own examples, you state that they were once part of metaphysics and then later found to have value.
  • Metaphysics Defined
    I would define metaphysics as follows: anything left over that won't be explained by more rigorous fields. To the extent that it has value, the field of being and content has been removed from metaphysics by physics, phenomonology, etc. To the extent that it has value, the field of causation and origins has been stolen by science generally and cosmology and evolutionary biology in particular. To the extent that they have value, the constants of nature have been annexed by physics. If any idea in metaphysics is found to have any value, it ceases to be metaphysics and becomes something else. Metaphysics is then all of the ideas that will never be found to have any value.Kenosha Kid

    If some fields of knoweldge were previously "removed", "stolen" or "annexed" from metaphysics by "more rigorous fields", then some ideas that were previously a part of metaphysics have been found to have some value. Therefore, metaphysics cannot be "all of the ideas that will never be found to have any value". I think you would need to qualify your definition of metaphysics as: "anything left over that [has not yet been] explained by more rigorous fields".
  • Eternalism vs the Moving Spotlight Theory
    Before this discussion exits to oblivion, I just wanted to add the (now probably rhetorical) question: What does motion mean in Eternalism?

    Eternalists can't say that something "has moved", "is moving", or "will move"; these are A-theory or Presentist designations which presuppose temporal passage. Without temporal passage, B-theory Eternalists can only say that "there is motion" at (or over?) a given time period, or length of time. But what does "there is motion" mean?

    One would assume it means the same as what Presentists mean by it: that a 3D object moves from here to there or changes spatial position over time (or wrt a change in temporal position). However, nothing changes temporal or spatial position in Eternalism. So, what is this mysterious motion of Eternalism? Earlier in the discussion, I was informed that such motion is represented by a gradient running away from the temporal axis, in contrast to a line running parallel to the temporal axis that represents no motion. However, the line running parallel to the temporal axis does not signify that a 3D object changes temporal position any more than a gradient running away from the temporal axis signifies that a 3D object changes spatial position. The line doesn't "run" at all.

    For the sake of argument, let's allow the Eternalists their motion. If we accept that there is motion between, e.g., t1 and t2, despite the fact that no 3D object moves or changes spatiotemporal position between t1 and t2, then how is this motion supposed to work? Will there forever be motion between t1 and t2? Does everything move "on the spot" or at each spatiotemporal position - without changing position? What is Eternalist motion if it is not a 3D object moving from here to there over time? Isn't this Presentist view of moving from here to there over time, or of changing spatiotemporal position, the only meaning that there can be of the word "motion"? What is Eternalist motion if not this?
  • Eternalism vs the Moving Spotlight Theory
    Hi @fdrake, yes that all sounds about right.

    Because objects are individuated by their temporal parts, a spacetime object which is characterised as moving from t to t' is actually changing identity over that time period. There's not "a spacetime object in motion".fdrake

    Yes, and since each 3D temporal part exists at its own spacetime location, then no part can move to another spacetime location that isn't occupied.
  • Eternalism vs the Moving Spotlight Theory
    Then this is not kinematic motion.Kenosha Kid

    Bloody hell, I know that. I'm trying to get you to disavow motion of a 4D object in the fifth dimension. But then you'd have to actually address my argument instead of just repeating your assumptions. Bye.
  • Eternalism vs the Moving Spotlight Theory
    Can you pin down where you think the inconsistency is? These are not contradictory statements. The first says that it doesn't matter for motion whether you think of a 4D object as one thing or a continuum of different things.Kenosha Kid

    You said: "It doesn't go away because you like to think of the hypersphere as being compromised of a plenum of 3D spheres". I think you meant "comprised". Nevertheless, the implication is that I "like to think of" a 4D object this way, whereas you do not.

    But I guess thinking of them as "a plenum of 3D spheres" must just be my crazy idea.
    — Luke

    I'm not arguing against it, it's just not the killer blow for motion you assume it to be.
    Kenosha Kid

    My argument is not merely that you can think of a 4D object as comprised of 3D parts. Perhaps you would care to address my actual argument.

    And I guess you're also back to talking about the motion of a 4D object without any qualms that this requires a 5th dimension.
    — Luke

    I never left.
    Kenosha Kid

    Motion of a 4D object means moving wrt the 4D universe. As you said: "moving wrt the 4D universe would be moving wrt a fifth dimension." If this is what you have been talking about all along, then we have been talking about different things.
  • Eternalism vs the Moving Spotlight Theory
    It doesn't go away because you like to think of the hypersphere as being compromised of a plenum of 3D spheres.Kenosha Kid

    Yes, I suspected that you might make this move. It's quite a departure from what you said just a day or two ago:

    They're the same object and it's the same motion, just different representations. The 3D object changes position with time: this is our everyday experience of motion. The 4D object changes shape with time: motion in 4D is geometry. They're not describing two different things but the same thing as two different representations.Kenosha Kid

    But I guess thinking of them as "a plenum of 3D spheres" must just be my crazy idea. And I guess you're also back to talking about the motion of a 4D object without any qualms that this requires a 5th dimension.
  • Eternalism vs the Moving Spotlight Theory
    No, motion is the gradient from a hyper-cylindrical (for a sphere) 4D geometry. You are conflating this gradient with movement with respect to the 4D block.Kenosha Kid

    No, I'm correcting you where you said that the 4D object "sometimes moves" wrt "its own temporal axis". I never asserted this. And you have identified the problem with that statement yourself: it would require a 5th dimension.

    Since motion of a 4D object does not make sense without invoking a 5th dimension - which neither of us want to invoke - then we can only be talking about the motion of a 3D object over time (over the 4th dimension). Right?

    If you are understanding me as you claim to, then you have read me as saying that a mountain literally lifts up from the horizon, rather than grading up wrt it. And yet somehow this goes unmentioned by you.Kenosha Kid

    I don't understand what you mean when you say "a mountain literally lifts up from the horizon, rather than grading up wrt it." I'm here to discuss Eternalism, not geometry. But I am willing to go along with your talk of geometry anyway.

    that motion in 4D is an inevitable feature of geometry, that you cannot have shape in 4D without kinematic motion.Kenosha Kid

    Are you familiar with begging the question?

    Your approach instead is very clearly about getting someone to explain the same thing over and over and over again in an as many different ways as they can muster in good faith, then claiming those difference approaches to be contradictions according to some bizarre logic.Kenosha Kid

    Demonstrate how it's bizarre logic. You barely address my arguments, which I've also had to repeat constantly. All I get from you is that motion is assumed in the 4D geometry or gradient without any supporting argument. The closest you have come to an argument is this:

    ... how can a 4D object have geometry and not kinematic motion? How can dx/dt be zero or undefined?Kenosha Kid

    I've already provided an answer to this question, which is the argument I keep repeating: the measurement of v=dx/dt assumes that the motion (v) is of an identical 3D object between t and t', but in 4D geometry there exist two non-identical 3D objects at t and t' (and at all times in between). Therefore, the assumption of an identical object moving or having motion between two times in Eternalism is false. In short, you can't calculate the motion of a 3D object between t and t' if it's not the same object at t and t'.

    In Presentism, an identical 3D object is assumed to leave t and travel to t', so it does not have this problem. You are attempting to insert this same Presentist motion into a 4D object, but it's just not there, either logically or physically. Motion is a Presentist notion. A cylinder cannot travel from one end of its length to the other.
  • Eternalism vs the Moving Spotlight Theory
    Then you are defining motion in 4D to be 5D, which is not standard kinematic motion. (We're going round in circles here.)Kenosha Kid

    What? You have said both that a 4D object "sometimes moves" wrt "its own temporal axis", and that a 4D object "moving wrt the 4D universe would be moving wrt a 5th dimension". As I pointed out earlier, you've contradicted yourself.

    If you're asking how it can be the same thing as geometry in 4D, do the maths: v=dx/dt in both representations. In 3D, 'dt' does not refer to a dimension. In 4D, it does, making motion a geometric feature.Kenosha Kid

    "dt" is a change in temporal position. In your view, does any part of a 4D object change its temporal position?
  • Eternalism vs the Moving Spotlight Theory
    But moving wrt the 4D universe would be moving wrt a fifth dimension.Kenosha Kid

    Exactly, which is why I'm questioning your statement that a 4D object "sometimes moves".

    The 3D (2+1) representation I posted from Huw Price's talk would, if the 4D object moved wrt the 4D block, be an animation, i.e. changing with a time that wasn't already in the picture.Kenosha Kid

    How is the animation supposed to work? What moves and how? Huw Price's talk contains only still pictures.

    They're the same object and it's the same motion, just different representations. The 3D object changes position with time: this is our everyday experience of motion. The 4D object changes shape with time: motion in 4D is geometry. They're not describing two different things but the same thing as two different representations.Kenosha Kid

    How can that be? A 3D object would be defined by a dimensionless point on the timeline, or a slice of the timeline. No 3D point or slice moves from one time or space to another. All points/slices exist at all times of the 4D object. A 3D slice cannot move from t to t' because different 3D slices (i.e. different 3D objects) exist at both times. The slice at t never leaves t, which means the 3D object at t does not move or go anywhere. You appear to simply assume that it goes from t to t'. If t and t' are the start and end points of a gradient, then surely you are talking about a 3D object moving from/between t to t', especially if the 4D geometry is but two different representations of the same thing.
  • Eternalism vs the Moving Spotlight Theory
    You have said that the 4D object does "sometimes move". Since you reject "the idea that the 4D object moves wrt the 4D universe", then with respect to what universe (3D? 5D?) does the 4D object "sometimes move"?
    — Luke

    Its own temporal axis.
    Kenosha Kid

    How is this not the 4D object moving wrt the 4D universe (an idea you reject)? The temporal axis is the fourth dimension. If the 4D object moves with respect to its own temporal axis, then surely it moves with respect to the fourth dimension or wrt the 4D universe.

    Likewise, motion in 4D is manifest as a deviation from, say, a purely cylindrical shape (for the case of a 3D ball).Kenosha Kid

    Is it a 3D or a 4D object that moves?