I thought this was the title of Harry Frankfurt's next book.

The existence of white wholes is close to being a logical consequence of the existence of black holes (plus some plausible symmetry assumptions). Most black holes are rotating. That is, they have non-zero angular momenta inherited from the conserved angular momenta of the collapsing stuff that made them up and that they later accreted. Rotating black holes are called Kerr black holes (strictly speaking only when they have zero electric charge, but that is inessential). Rather than having a point singularity (as have non rotating black holes) they have an annular singularity. If one falls into a Kerr black hole from a direction outside of its equatorial plane, then one ought to be able to go trough the annular singularity while not getting crushed, nor stretched by huge tidal forces, provided only the Kerr black hole is large enough, and it has sufficient angular momentum, as might be the case with many massive black holes that are located in galactic cores. If the metric of space time past those inbound trajectories into the annular singularity is symmetrical with the metric in the "inbound" region, then a falling traveler (or any inbound object) ought to emerge from the black hole somewhere, from a white whole, presumably. Where would one emerge, and whether this would occur somewhere in this universe at all, is anyone's guess.

Right. So maybe it's not so much the CO2, but the massive deforestation that is happening. — Harry Hindu

Not sure what you mean with "not so much..." It's not either one or the other; it's both. According to an IPCC AR4 figure (fourth assessment report) the "CO2 equivalent" net emissions from deforestation and biomass decay represents 17.3% of the total anthropogenic contribution to the enhanced greenhouse effect, while the fossil fuel burning contribution is 56.6%. (The rest is from N2O, CH4, other greenhouse gases and other anthropogenic sources of CO2 such a cement production.)

Right, it's rhythmic. CO2 drops during southern hemisphere summer, if I recall correctly, and goes up in the winter. — Mongrel

Yes, this seasonal cycle occurs because of the annual death and regrowth of land vegetation over mostly northern hemispheric land masses.

As I said before, we put CO2 in the environment just by breathing. — Harry Hindu

Our exhaling CO2 through breathing is part of a carbon neutral cycle and didn't have any direct incidence on the recent increase of atmospheric CO2 concentration. That's because the CO2 that animals (including us) exhale all comes from plant food and the pants that are eaten already had extracted this CO2 from the atmosphere through photosynthesis. So, through this whole nutrition/metabolism cycle, as much CO2 is taken out from the atmosphere and continuously incorporated into the biomass as is continuously emitted by it (including through fermentation of dead biomass). By contrast, the CO2 that we release through burning fossil fuels had previously been stored underground over hundred million years and now is released back by us into the atmosphere in a time frame of mere decades. This is why current atmospheric CO2 concentration is higher now than it has been over the last million years (and likely much longer) and still is climbing at breathless speed (pun intended).

That is why, pragmatically, I am able to agree with Aletheist's point about identity, in the case of an artefact, being a matter of designation - because a ship is not a being, but a collection of parts, and as such, has no intrinsic identity. It is what it is, purely as a matter of designation. — Wayfarer

That would be to say that artifacts and inanimate objects (such as rocks, planets, storms and rivers) have merely nominal essences while only human beings (and possibly plants and non-rational animals) have real essences. But I thinks that's too sharp a dichotomy. Artifacts and inanimate objects may only have being though their being embedded into the practical form of life of human beings, but that is enough to confer them essences of a stronger sort than merely nominal essences as traditionally conceived, or so it seems to me. Conversely, there also is a need to pragmatize our own essences in something like the Sartrian existentialist fashion. We have some inescapable freedom (however constrained) and responsibility to make ourselves the sort of thing that we essentially are, and not just to build artifacts, or cognitively carve nature, in accordance with our given needs and interests.

That would be the ship with all its "accidents"... — apokrisis

Thanks. There is much to agree with in you post, and maybe some to disagree with (or to clarify about my own position) but I must give to what you have written much more thought.

The identity at issue in this thread regarding the ship of Theseus is a relations between particulars. This relations is also called "numerical identity" and can be defined as the relation that each and every particular holds with itself and nothing else. It is what Leibniz's law(s) is (are) about (i.e. the identity of indiscernibles and the somewhat less controversial indiscernibility of identicals). If the identity of A and B were simply a matter of them being instantiations of the same type, then Leibniz's law of identity of indiscernibles would be quite trivial while his law of indiscernibility of identicals would be trivially false rather than trivially true. Wayfarer also would be identical with John, presumably, since both are instanciations of the type "human being".

Also, numerical identity is not a relation that holds between species (as opposed to genera) but rather between particulars (as opposed to universals). The general/specific distinction is not the same as the universal/particular distinction. (Distinguishing clearly those two distinctions has payoffs in the philosophy of law, the philosophy of action, and meta-ethics, as Richard Hare and, following him, David Wiggins, have suggested.)

No, a ship reconstructed from discarded parts could never qualify as the original for two reasons; firstly because it would not replicate the physical condition the ship had been in at any point in its history, and secondly because those discarded parts had ceased to be part of the ship, and had remained so for varying periods, and had thus not participated in its entire history. — John

It could actually come even closer to replicating the physical condition the ship originally had been in than the continuously maintained ship does. Your second objection, if valid, would entail that a fully disassembled object could never be reassembled as the same object it originally was. Disassembling a piece of furniture for purpose of shipping, for instance, would amount to irreversibly destroying it, on your view.

It's true that replacement parts did not participate in the entire history of the ship either but current parts had become part of the ship and remained so until the time when any substitution might be proposed.

This doesn't explain why, on your view, some objects can't still persist in disassembled states, or, at least, couldn't be brought back into "active" existence as (numerically) the same objects that they originally were before disassembly. What if you are chopping some wood and the head of the axe flies off the handle. After you've glued the two parts back together, is it necessarily a new axe that you have now manufactured, on your view? Why might this not count as your having repaired the old axe?

The identity of the ship does not reside in any part, but in the whole structure, with its entire historical trajectory and facticity.

Yes, I agree with this but I would go eve further and -- following darthbarracuda -- I would potentially include the ship's external relationship to *other* things (including ourselves, our pragmatic interests, and our conceptual skills) as part of the determination of the objects identity though time (or as part of the transcendental constitution of the object's form, to put it in a Kantian/Aristotelian way).

What other reason can you think of for the parts of a ship being replaced over time other than their dysfunctionality or lack of aesthetic appeal? — John

The reason why someone might collect the discarded parts might be because she sees the process through which a ships is being continuously maintained and repaired through substitution of material parts to amount, in this specific case, to a progressive destruction of a historically significant artifact and she hopes to, some day, be in possession of all the original parts and to be able to reconstitute the original. Your insistence that this is not possible because the continuously maintained functional artifact *is* (and remains) *the* original "ship of Theseus" is begging the question against her.

I don't see a paradox, even in that case. In that case the unused ship rebuilt out of unattractive parts would be the fucking ugly Ship of Theseus. Even if it were used by a different crew it still wold not be called 'the Ship of Theseus'. If it replaced the Ship of Theseus then it would be the replica built out of old ugly parts that became the new Ship of Theseus for some stupid reason. — John

You seem to be arguing that, in a case where some artifact is being disassembled and later reassembled, then what determines the identity of the reassembled artifact with the original is the beauty or ugliness of the reassembled object, or the wisdom or stupidity of the motivation for assembling it. What if there were an wise and intelligent motivation for reassembling a ship from its original parts, and the reassembled item would be even prettier than the continuously repaired ship?

If they had been individually defective, then what kind of a ship could be built out putting them all back together? The fucking useless Ship of Theseus, perhaps? — John

You can imagine a variation of the story where the planks have been replaced for merely cosmetic reasons and the paradox remains.

As I said before, I am on board with doing what we can, but it will require reaching widespread consensus on both the problem and the solutions. — aletheist

The main obstacle to reaching consensus on the existence of the problem (and the anthropogenic cause of global warming) is the politically motivated resistance of Republicans in the American Congress.

'Inconvenient Truth' showed ten years ago that the accumulation of greenhouse gases in the atmosphere has been clearly measurable since the 1970's when observations started being made in Hawaii. — Wayfarer

Just picking a nit: The continuous Mauna Loa CO2 record reaches back to 1958. There are earlier spot observations when Charles Keeling was refining his pioneering measurement methods.

Even if I grant that there is "a preponderance of evidence" for this, it does not rise to the level of being "beyond a reasonable doubt." — aletheist

This is a standard of evidence that is required before a jury delivers a verdict of criminal culpability, such that the convicted individual is liable to be jailed. If the way in which you are cooking you chicken is liable to burn the house down, then "proof beyond a reasonable doubt" isn't required to justify finding a safer way to cook your chicken.

What something is is not simply a question of its material constitution but of its relationship to other things as well. — darthbarracuda

This is a very important point. — aletheist

This is a very important point indeed. While trying to find out ways of explaining "top-down causation" to some friends of mine, this has come close to becoming my philosophical motto.

When this point is not sufficiently attended to, then the relation of material constitution becomes liable to be confused with numerical identity. But something can persist through time as the thing it is (and remain the same individual) while gaining and/or losing material parts. So, material constitution isn't identity. The statue isn't (or need not be) the lump of bronze that it is made of since it can be destroyed while, at the same time, the lump of bronze persists. Likewise, a ship isn't (or need not be) the set of planks that make it up -- even with the qualification that the planks remain suitably arranged so as to preserve its function -- since the ship can persist through the replacement of some (or even all) of its planks.

Those considerations, though, only partially solve the paradox of the ship of Theseus. I owe the fuller illumination of this problem to Peter Simons (Parts: A Study in Ontology, OUP 1995/2000) and David Wiggins (Sameness and Substance Renewed, Cambridge University Press, 2001)

The trouble with the standard telling of the story of the ship of Theseus is that, while it makes explicit the issue of the relationship of "the ship" with its parts, it obscures the fact that there are actually two different contenders for being the object singled out as "the ship" (since "ship" signifies two different sortal concepts with incompatible persistence and identification criteria associated to them, as explained below); and both of them metaphysically relate to their parts in different ways thus pulling our intuitions regarding the persistence and identity conditions of this (ambiguously named) object in two different directions.

There is first the historical artifact -- some sort of a relic -- that we may think of as "the ship of Theseus" and which is such that we do care very much about its retaining at least some -- and maybe most -- of its original constituents. Else, at some point in time, it ceased to be what it was qua historical artifact (or relic). The same is true of most works of arts, such as a Picasso painting say, where we do care that the canvas, or paint, not be replaced even as the form might be maintained.

And then, secondly, there is the functional artifact -- the seafaring vessel -- that retains its identity through carrying forward its function (through maintenance and repair, etc.) This object is not the same thing that we previously named "the ship of Theseus", though nothing prevents us from giving it the same name, just as two different men can be called "Peter". The crucial thing is that, whatever name we give "it", the "it" that is at issue very much depends on the way "it" (and the sets of its material parts) not only hang together, functionally, but the way in which "it" (and the relevant function) relates to our pragmatic interests. Since nothing stands in the way of our having simultaneous pragmatic interests in singling out more than one object -- e.g. an historical artifact and a functional artifact -- then, it may occur that the original "ship of Theseus" (as singled out at the moment of its historical origin -- had material constituents that make up two different objects that merely happen to occupy the same space and share the same material constituants at that point in time but are liable to have divergent histories, spatial trajectories and material constituants some time in the future.

At the end of the story, there is one historical artifact that is identical to the original "ship of Theseus" (the historical artifact that essentially originally belonged to Theseus) and another, different, functional artifact that is identical to the original functional artifact that we also want to name, misleadingly, "the ship of Theseus". This is the functional seafaring vessel that, as it happens, originally but non-essentially belonged to Theseus. Just as is the case for the statue of Hermes and the lump of bronze that materially constitute it at a time, those two "ships" (qua historical artifact and qua functional artifact) are two different objects.

(This accounts rests on David Wiggins's thesis of the sortal dependence of identity, whereas the account earlier suggested by Wayfarer relies on the thesis of relative identity, defended by Peter Geach. I think Wiggins's account accomplished what Geach's account seeks to achieve while eliminating its severe logical problems)

Thus there are more facts than members of T, therefore no "totality of facts" can exist QED. — tom

You've only shown there to be no infinite and denumerable totality of facts. There could still be a finite, or a non-denumerable, totality of facts. At any rate, that would not be ruled out on the basis of such a proof.

There's no way of adjudicating what 'maximally great' might be. (Mermaid beauty contest? Who would be called on to judge?) — Wayfarer

Why? Cartoon Donald Trump, of course.

If you are going to quote, then the name is "Consistent Histories" or "Decoherent Histories". — tom

Yes, I meant "consistent histories". Thanks. Michel Bitbol's paper Decoherence and the Constitution of Objectivity is relevant to this discussion, as well as Rom Harré's The Transcendental Domain of Physics, both published in Constituting Objectivity: Transcendental Perspectives on Modern Physics, Michel Bitbol, Pierre Kerszberg and Jean Petitot, eds.

Right! Because the Aristotelean term for 'substance' was originally 'ouisia', which is nearer in meaning to 'being' than to what we now designate as 'substance'; and only beings are 'bearers of predicates', or 'subjects', per se - '[primary] substance is that which is always subject, never predicate'. So this enables a distinction between the nature of 'beings' and 'objects', which I think has been subsequently lost or forgotten. — Wayfarer

Yes, living things, for Aristotle, are the paradigms of substance in the strongest sense. They display a unity of mater and form in the sense that their identifiable proper parts only are active qua essentially being parts of those beings (i.e. having as their proper function to sustain the characteristic activity of the substance they are a part of). The human heart is essentially a part of a human being, and so is human blood, human bone tissue, etc. This is why the elements also are considered to be primary substances according to Aristotle, for there is no part of fire that isn't essentially fire (according the the ancient Greek conception of fire as one among four elements, of course). Still, my point was that under this construal, artifacts, stones and planets also are primary "beings", i.e. primary bearers of high-level predicates that only apply to beings of that kind. It just so happens that they are imperfect substances, in a sense, since their matter is imperfectly united with their form. Their overarching forms (i.e. their essential qualities or functions) only partially inform the structure of their parts, and those parts thus retain a unity of form that is alien to the substances they are constituents of. For instance, a chair can be made made of wooden planks that retain their identities as wooden planks while they merely (and accidentally) lay a hand, as it were, to enabling the characteristic function of the chair (and thus, also, enable its existence qua functional artifact) while they are well fitted parts of it.

But my main point was that Kant is justified in using his category of substance with the broader extension (to encompass "imperfect substances") since it functions as a necessary formal principle of the intellect that allows us to gain empirical knowledge of all sorts of material "beings" (e.g. boats, planets, rocks) other than just living organisms or chemical elements. My main aim in bringing those metaphysical considerations to bear on the present discussion was to show why and how our conception of "planets" (a "sortal concept", which is a concept of a "substance" in the broader, imperfect sense) still must be presupposed to be operative in the asking of the question regarding the existence of the Earth in the distant past. It is this concept of a planet, incorporating the understanding of its specific mode of existence, that determines the truth conditions of the intelligible claim about the past existence of the object, regardless of the fact that the bits of rock and magma that make up the planet may have a somewhat "accidental" (imperfect) unity from a scholastic point of view.

I think there's a bit of equivocation going on here. It think that Newtonian physics only deals with mass, not 'substance' in the formal sense, the sense of which you so ably set forth in your earlier response to me; in fact it's this very point which differentiates modern physics from its Aristotelean precedents. — Wayfarer

The difference may cut even deeper if, as Aaron R mentioned in another thread, true Aristotelian substances are unities of matter and form, of dunamis and energeia. In that case, the only true substances are living organisms, and also, arguably, pure chemicals or chemical elements (as argued by Aryeh Kosman in The Activity of Being: An Essay in Aristotle's Ontology). Artifacts and non-living objects like stones and mountains are substances only by analogy. (The unity of their material parts is accidental according to scholastic metaphysics). This definition, though, may be a bit too narrow for purpose of Kantian epistemology. Kant's category of substance has wider extension. If we thus broaden the strict Aristotelian concept to encompass any enduring object ("continuant") then we lose the intimate unity of matter and form but we get a formal concept of substance more suited for analyzing the variegated ontologies of the "special sciences" (and our empirical cognition of their objects) and of the many areas of the human world.

What classical mechanics typically deals with are such things as idealized point particles, rigid bodies, homogeneous incompressible fluids and unbreakable ropes. Real objects that approximate the behavior of those things (gas molecules, liquid water, billard balls, levers, planets, etc.), considered over short enough time frames and gentle enough mutual interactions, can be considered the "substances" of classical mechanics -- a science not concerned about attributes of "form" other than mass, geometrical shape, and the object's powers to exert Newtonian forces on one another (or to generate force fields). The massive objects that thus approximately obey the laws of classical mechanics, and considered merely as such, still have individuation and persistance conditions, albeit trivial ones (since they don't undergo generation, corruption or mereological variations). They are re-identifiable enduring objects and Kant's arguments in his Analogies of Experience speak to our concepts of them (among very many other concepts that are alien to physics proper). They also have specific powers. They are typical substances in the broad sense of contemporary analytic metaphysics (Peter Strawson, David Wiggins, ...) that owes as much to Kant as it owes to Aristotle.

Were the questions distinctively mathematical/logical? Was there some scientific or philosophical theme that you remember (e.g. paradoxes of physics, ethical dilemmas... ?

Does that not belong to the Metaphysics as art thread? In any case, please mods, don't delete it!

I don't think I would agree with this statement, specifically the part about enduring substance not falling under the purview of physical law. I think that Newton's first law, sometimes called the law of inertia, provides the formal concept of enduring substance. I admit that this law takes enduring substance for granted, but that's what laws of physics do, they take for granted what the law states. What this laws says, is that any substance will continue to exist, exactly as it has, in the past, unless acted upon by a force. So what this law does is describe enduring substance, as that which continues to exist as it has, in the past, unless it is acted upon. — Metaphysician Undercover

It is a very specific sort of substance that strictly obeys Newton's first (or second) law. It's a substance that is either defined as the mereological sum of its material parts, or that consists in an essentially indivisible mass. Substances that can survives the loss of some of their massive parts, or maintain their identities though the accretion of new massive parts, such as plants, animals, most artifacts, and celestial bodies, don't strictly obey Newton's laws of motion precisely because of the principle of conservation of momentum (which is a consequence of those strict laws). Those laws only strictly apply to physical "matter", things that have invariant mass. When an ordinary substance gains or loses parts, conservation of momentum only applies to the unchanging mereological sum of this substance and of the parts that it either lost or gained.

What the laws of physics are quite silent about -- and this was my main point -- are the principles that govern the conditions of persistence and individuation of ordinary empirical substances. This falls under the purview of irreducibly "higher-level" laws (such as the laws of biology) or depends on human conventions possibly tied up with specific pragmatic interests, in the case of artifacts, or some combination high level-laws and conventions in the case of objects that fall under semi-technical concepts such as planets, mountains, etc.

We could possibly design a robot to be conscious like humans. If they could create a model of sensory information and use that model to navigate the world and to contemplate themselves being aware of their world, then why would we say that this robot isn't conscious, or self-aware? — Harry Hindu

For sure. Such a robot would be aware that there are objects its world. This sort of objective empirical knowledge is dependent on the existence of a form of reflexive self-knowledge about ones own capacity for empirical knowledge (and of its fallibility -- the possibility of illusion). This robot's awareness, accompanied by self-awareness, would be qualitatively distincts from a cat's mere awareness of mice in its vicinity. That's something that falls short from an awareness that there objectively are mice in its vicinity.

There is more to having the relevant form of self-consciousness than possessing a descriptive "self-model", though. (Aristotle hints at the relevant distinction with the example of the physician who heals herself. There are two distinct ways one can heal oneself: as one would also heal another, through "prescribing" oneself exercise or some medicine, say, or spontaneously, through merely facilitating the natural process of cicatrisation, say. The relevant sort of self-knowledge that grounds empirical knowledge is likewise "spontaneous", in a sense. It characterizes the form of empirical knowledge -- that is: the form of the conceptual activity involved in the shaping of the experience, with the tacit self-acknowledgement of the epistemic responsibility from the knowing subject in bringing to bear the right concepts to her experience -- rather than just specifying its object by description as just one more item in the world who merely happens to refer to herself as "I".

The Myth of the Given is the one essay I have read, albeit, probably not very well or deeply. — Wayfarer

I was unaware that Sellars had written an essay with that title. Are you sure? John McDowell wrote Avoiding the Myth of the Given a few years back...

I am perturbed by the reference to materialism. I think I understand that Marx's interpretation of materialism is historical and economic, but I'm afraid I always tend to see materialism as being the prime philosophical adversary. Elsewhere, his books are referred to as an effort to re-vitalise the German idealist tradition. So I'm a bit nonplussed by that. — Wayfarer

I wouldn't make too much of that. This surprising gloss that Rödl has chosen to put on his project makes him no more of a materialist than Aristotle already was. Rödl's work "naturalizes" Kant, in a sense, through displaying how human beings, who are finite and essentially embodied substances, (in Aristotle's sense), and hence "material", can nevertheless gain a priori knowledge of the form of their own intellects in virtue of them already embodying this form as a rational capacity (rather than gaining knowledge of it empirically, which would be a sort of psychologism). Also, there is no mention of Marx or of materialism in Categories of the Temporal (and only a passing reference in just one chapter of Self-Consciousness).

Let me also reference this excellent albeit very short review of Categories of the Temporal by Aloisia Moser. (This is a direct link to the pdf file)

There is no measurement problem in realist no-collapse QM. — tom

Even in no-collapse intepretations, there is a process of decoherence into "coherent histories" (analogous to the "worlds" of the many world interpretation) that takes place. Coherent histories are correlated to (or "relative to") the macroscopic states of measurement apparatuses, or of the embodied human observers themselves who actively single our aspects of the world to observe, and who don't conceive of themselves as sorts of queer superposed Schrödinger cats). This is what "relative state" refers to in Everett's "relative-state formulation of QM".

So, in all the common interpretations of QM, including "no-collapse" interpretations, there always is a tacit reference to measurement operations, and the choice of the setup of a macroscopic measurement apparatus always refers back to the interests of the human beings who are performing the measurement. The processes of either "decoherence", or "collapse" of the wave function, (or of "projection" of the state vector), amount exactly to the same thing from the point of view of human observers. In order to escape this essentially perspectival human predicament, and ignore the measurement problem, you have to label all of empirically observable reality an illusion and proclaim the mathematical abstraction represented by the Schrödinger wave function of the whole universe "reality". "Reality," as you conceive of it, is beyond the reach of observation, or of our own empirical concepts.

...the subject of the criticism by Sellars in his essay 'the myth of the given'. — Wayfarer

You must be thinking of Empiricism and the Philosophy of Mind.

I notice that two of Sebastian Rödl's books are available in my University library, and thanks for alerting me to him. — Wayfarer

Those must be Self-Consciousness and Categories of the Temporal: An Inquiry into the Forms of the Finite Intellect. The latter book appeared last in the English translation (slightly updated, it seems), but was written by Rödl first in German (Kategorien des Zeitlichen: Eine Untersuchung der Formen des endlichen Verstandes). Although Self-Consciousness is excellent and, among other achievements, clarifies some core aspects of John McDowell's epistemology, Categories of the Temporal is my favorite and is an unmitigated success, in my view. It may be worth reading first. I have only one small reservation regarding one subsidiary thesis -- about the divisibility of movement -- that is not damaging to the main argument at all.

Except of course, it is the very theory that reveals the block-universe to us - i.e. that the B-Theory of time is true - that explains the formation of planets and correctly predicts their orbits. — tom

I never questioned the explanatory and predictive powers of the special or general theories of relativity, or the heuristic value of the "timeless" metaphysical pictures that they may suggest (for mere purpose of physical explanation). This picture of complete determinacy of the future (given some fully determinate specification of energies and momenta in some space-like surface), of course, rubs against the indeterminacy inherent to quantum mechanics. Only through endorsing a time-independent state formalism can you attempt to reconcile QM with the block-universe view, as you are wont to do. But this is to gloss over the measurement problem of QM and the fact that the measurement operators carry over the time-dependence of actual measurement operations (e.g. though specifying the time-evolving basis of the projection of the time-invariant state vector, in Dirac's formalism.)

The idea that two distinct objects have "simultaneous experiences" is what, in the past, grounded our notion of objective existence. This gave us the notion that distinct things had something in common, the experience of time passing. This thing which they have in common was called existing. The precepts of special relativity do not necessitate that we dismiss this objectivity in favour of the block universe. — Metaphysician Undercover

Yes, of course. That was part of my point.

What special relativity indicates is that there is vagueness with respect to "simultaneous experience". How we understand "simultaneous experience" greatly influences how we produce laws of physics. So there is variance within the laws of physics depending on one's interpretation of simultaneous experience.

Special relativity relativizes the concept of simultaneity to "inertial frames of references" that are used to operationalize this concept (with the notional use of sets of co-moving rulers and clocks) as well as the concepts of physical length and duration. It doesn't have much bearing on the ideas of simultaneity or succession of perceptual experiences of rational agents as Kant was making use of them. That's because those concepts, as used by Kant to investigate into the grounding of empirical knowledge, are revealed to be tied up with the concept of an enduring substance and such a formal concept doesn't fall under the purview of physical law.

Physicists talk about specific substances all of the time (e.g. atoms, rocks and planets) but they rely on ordinary concepts of enduring material objects that fall under common sense sortal concepts with their associated persistence and individuation criteria, which physics as such says nothing about. Physicists usually are philosophically naive about substances. They fail to notice that their knowledge of ordinary objects (singular substances) isn't informed by physical theory. They also tend to fail to notice that singular substances as such only obey the so called laws of physics approximately and fallibly (e.g. on the condition that they don't change shape, don't lose or gain material parts, etc. etc.)

My argument is not that the world doesn't exist in the absence of any or all observers, but that whatever we can say we know about what exists, presupposes a perspective. Even if that is mathematicized, which effectively eliminates purely individual perspectives and gives a kind of 'weighted average' of all points of view, it's still an irreducibly human point of view, which is inextricably an aspect of whatever we say exists. — Wayfarer

I agree. Your view contrasts with the view expressed by Sean Carroll (quoted) in the OP of this thread. Physicists often are happy to equate "the Universe" -- the totality of what exists -- with some comprehensive set of "initial conditions" conjoined with a set of universally quantified statements ("universal laws"). Everything (i.e. every empirical truth; every state of affairs) is supposed to be determined by the initial conditions and the laws. This is a view of the "block universe" in which time just is another dimension akin to the three spatial dimensions. The human perception of the flow of time is alleged to be an illusion stemming from of our merely subjective perspective, not just in point of temporal scale, as mentioned by Wayfarer, but also regarding the distinctions between present, past and future, which are taken not to be of any relevance to the objectively existing fabric of the world. Hence, Sean Carroll is led to downgrade the objectivity of the very notion of causality. In his view, nothing ever really comes into existence. The "block universe" being "eternal" at a fundamental level, events (or states of affairs) need not be caused to occur (or to be as they are) since the laws of physics govern everything and the way in which they govern consists in them fully constraining the mathematical relationships between the layout of the universe at all the singular moments of time (i.e. in between elements of a full set of space-like slices of the eternally existing "block universe").

Such a view of the universe can't of course mesh with our view of the world as a source of possible objects of experience. Kant argues in the Analogies of Experience (in his CPR) that an empirical experience can't have an objective purport if it doesn't potentially rationally bear on other experiences. (Wilfrid Sellars also argued for this in his Empiricism and the Philosophy of Mind currently being discussed in another thread). And this is only possible if we can distinguish the successive experiences of a single thing that has changed from the simultaneous experiences of two separately existing things. The possibility of our conceiving of this simultaneity/succession distinction, in turn, depends on our ability to recognize laws that govern the evolution of enduring substances (i.e. laws that state their persistence conditions and their fallible (active and passive) powers. (Why those powers must be fallible is explained by Sebastian Rödl in his book Categories of the Temporal). If it were conceivable that any "substance" could be experienced to have become any other "substance", with no law governing how its qualities tend to change over time, then there would be no telling if two qualitatively distinct experiences refer to the same object (at different times) or to two distinct objects (at the same time). Thus, the possibility of the objectivity of experience presupposes the possibility of the experience of time (as a formal condition, rather than as a material content) and the possibility of the experience of time, in turn, presupposes the ability to recognize substances governed by laws. So, in sum, the category of a substance -- of an enduring object that can be experienced at different moments of time and that is governed by laws that specify its powers -- must be brought to bear by an experiencing subject to all her experiences if they are to have objective purport at all. If this is right, the formal concepts of substance and of time are prerequisites of the intelligibility of the world.

But, can't the world be simply conceived to exist (i.e. be intelligibly be judged to exist) without its satisfying the condition of its also being a potential object of experience by agents possessed of finite intellects like us? This was the issue being discussed by Agustino, John and Michael regarding the existence of the Earth before there were humans experiencing it. It is important to recognize that the Earth is a potential object of experience of a distinctive formal kind. It is an enduring substance. As such, it doesn't exist qua object of experience independently of the specific substance concept that it is taken to falls under -- e.g. the concept of a rocky planet -- which specifies its conditions of persistence and individuation. Those conditions are tied up with the concept and aren't independent of our interests in individuating it thus. If we wonder at what point in time the Earth began to exist, for instance, this question can't be made sense of quite independently of our criteria for an object's inclusion into the (substance) category of a rocky planet. So, this is why the claim that the Earth existed before there were humans quite independently of whatever humans ever thought regarding what it is that makes a planet the sort of thing that it is doesn't quite make sense. The existence of the Earth, qua possible object of experience, doesn't depend on there actually existing humans actually or potentially experiencing it, which is something Agustino would be correct about if it were his only claim. But the very sense and intelligibility of the state of affairs being considered -- e.g. that the Earth existed three billion years ago -- is relative to some substance concept or other that corresponds to the specific interests of a potential subject of experience.

Sean Carroll's block universe, as he conceives it, within which time just is an objective parameter, doesn't contain any planet because this conception lack any criterion according to which some set of "particles" does or does no make up a "planet" in any specific space-like slice of his "objective" (so called) universe.

And then I think that it is difficult to be conscious of something else and not to be conscious of myself or to be conscious of myself and not be conscious of other things. I think that one implies the other. You mean that these philosophers say that self-consciousness is not about that? — mew

No, I think you're right about that. Your being aware (i.e. having the perceptual knowledge) that there are objects in the world that exist independently of your perception of them requires awareness that you can potentially experience them -- i.e. that they be potential objects of experience. You arrived at this conclusion without Kant's help. Congratulations!

The brain is computationally universal, but the mind certainly is not. There are many operations a mind will not perform, for reasons as diverse as morality and boredom. — tom

This doesn't show that humans can't perform those operations; only that they may occasionally choose not to. Humans don't really instantiate universal Turing machines because they are finite mortal beings, but then so are human brains. But I don't quite know what your argument is anymore. You seemed to be arguing that the mind was the software of the brain, quite literally. Your ascribing vastly superior computational powers to brains than you do to people supports this contention how?

Brains don't give a damn either.

On this, at least, we agree.

If plants are conscious but their reactions are just automatic, — mew

The recent movie Sausage Party makes the case that some edible plants (and other food items) may achieve self-consciousness at the moment when they arrive to the supermarket.

Thank you, even though I don't understand at all what you mean in your second paragraph — mew

I meant to explain that there is a sense of "self-consciousness" that doesn't refer to the mere outcome of turning one's own gaze inside, as it were, and contemplate what it is one is feeling, experiencing, etc., but rather is a form of critical reflection on what it is that is required to make sense of one's ability to know the world on the basis of experience, or to know what it is one ought to do (and that one is actually doing or intending to do -- i.e. practical self-knowledge) on the basis of practical deliberation, and that reveals explicitly features of our rational abilities that are necessarily operative in every mature human being, including those who don't critically reflect on them. Immanuel Kant is one fellow who pioneered this sort of reflection and Sebastian Rödl is traveling a parallel path.

Are these books you mentioned easy to understand? Or do you know any other books or sites where I can read about philosophical ideas in easier language? — mew

The book by Sebastian Rödl is quite technical and requires some philosophical background. The book by Bennett and Hacker, though, is written in very plain language and is intended for a broad audience of non-specialists. It is a very fine introduction to the philosophy of mind and of cognitive sciences.

If in daily someone asked me, I would say that to be conscious is to recognize that I'm having an experience. But this implies that I'm also aware of myself, so then how is self-consciousness different from consciousness? And how science or philosophy use these words differently? — mew

Well, self-consiousness is the topic of the next chapter in Bennett and Hacker's book. This may not be a phrase that has had an ordinary use before philosophical and cogsci theses began to seep into popular culture. I may surmise that nobody has a view on what "self-consiousness" refers to which roams free of some loaded theoretical standpoint or other.

Sebastian Rödl wrote a very nice book titled Self-Consciousness. His approach is resolutely Kantian, and he has no concern for qualia or for passive introspection onto the quality of ones own private mental life. "Self-consciousness", in his book, rather refers to the tacit a priori knowledge that rational agents have of formal features of their own perceptual and agential abilities.

Do you mean that what it is depends simply on the context of our discussions? Can't we just use the word wrongly? — mew

Yes, we can use the world wrongly. But when we are simply ignorant of hidden features of the objects or phenomena that we are talking about, this need not signal that we are misusing the words and don't really know what we are talking about. Maybe science can enlighten us on underlying mechanisms, or the way known phenomena are realized, or disclose hidden properties that they have. But this would not necessarily show that we have initially misidentified the objects or phenomena talked about, as Michael's examples illustrate.

Also, there is another way to misuse a word which is to use the name a phenomenon talked about in ordinary life (i.e. in non-scientific discourse), theorize about its referent, and then confuse the phenomenon of ordinary life with the theoretical entity postulated for purpose of scientific theorizing. Hence "consciousness", for instance, which was not originally conceived to be designating an object of awareness when we understood what it means for someone to be conscious, or unconscious (intransitive use) or to be conscious of something (transitive use) comes to seem to designate an object of private acquaintance. This is because the semi-technical uses fostered by the philosophy of mind, or by cognitive science, led us to misuse the original term, and we lost track of the familiar phenomenon that we originally were intending to explain.