Is the PSR manifest in 'causality'?

If you take the sufficiency rider seriously, then any answer in terms of causality needs to answer the further question: but why 'this' cause and not another? (+ further question re: individuation of causes; what makes a cause a cause and not another...).

(+ further question re: individuation of causes; what makes a cause a cause and not another...). — StreetlightX

But, all this is nonsensical in the Many Worlds Theory. Nothing in particular is special because absolutely everything is.

Which would work if and only if causality is restricted to operating on the microphysical realm, which is contentious to say the least. It also displaces causality from being an intra-worldly phenomenon to an inter-worldly one, which is a displacement of the question. We generally ask the question to know about changes or entities in this world, and not others.

Hume performed intellectual somersaults in an effort to satisfy the PSR in regard to induction. At what point did he reverse course?

Posty operates under the misapprehension of the "Many Worlds" interpretation of QM as some some sort of anything-goes modal realism.

Lewisian modal realism dissolves the PSR, in the same way that the guillotine cures a headache. You can no longer demand an explanation for why A rather than B, since you've already assumed A and B (and C and D...)

Sorry, you'll have to direct this question to someone who knows more about Hume.

An Enquiry concerning Human Understanding, §4
Where he expounds on the tenuous nature of Induction whose knowledge depends on experience..."the influence of custom, that, where it is strongest, it not only covers our natural ignorance, but even conceals itself, and seems not to take place, merely because it is found in the highest degree." 4.24

"What is the foundation of all conclusions from experience?"

We look at the past and we assume the future will repeat its past. "From causes which appear similar we expect similar effects. This is the sum of all our experimental conclusions." 4.31

His argument brings into question the uniformity of nature, why should we suspect that nature is ceteris paribus uniform.

This the point that Quentin Meillassoux discusses in 'After Finitude' in his chapter "Hume's Problem page 91.

What I wanted to address was the notion that a PSR of some sort is indispensable to our everyday thinking (basic principles of thought frank) and to science. I argue the opposite. Both everyday thought and science are oblivious to the PSR, unless they specifically focus on the question. — SophistiCat

I don't think it matters to the argument whether the PSR is present, as a formulated principle, in the minds of everyday people and scientists; the important point is whether they operate on the implicit understanding that everyday events and the objects of scientific study are capable of explanation. And I think the answer to that question is very obviously 'yes'.

For me, Della Rocca's understanding of Hume's and Kant's projects is wrong-headed, if that passage you quoted is anything to go on.

Hume denied that we can observe causation, and he claimed that the idea results merely from habit due to observing invariances; the constant conjunctions of certain events. Hume's avowed aim was to do for human nature what Newton had done for nature; and he could hardly do that unless he was convinced that human nature is susceptible of explanation!

Kant, on the other hand, responded to Hume by claiming that the objects of experience must conform to the human experience and understanding, and that since causation is one of the central pillars of human understanding, without which, for Kant experience would be unintelligible; it hardly seems right to claim that Kant wanted to claim the PSR is false.

What Kant did do is argue that the ambit of PSR is limited to the empirical, that it is, in other words, an epistemological principle. Kant rejected only that it can be extended to the metaphysical or ontological; and this is just what I have also been contending in this thread, that the PSR has provenance only insofar as it is an epistemological principle.

The quote from Carroll that you gave seems to be an attempt to speak to the ontological, which is what both Kant and I say cannot be coherently done.

When he says:

I argue that any attempt to account for the existence of something rather than nothing must ultimately bottom out in a set of brute facts; the universe simply is, without ultimate cause or explanation. — Sean M. Carroll

He is either making an illegitimate claim or else more modestly stating the self-evident: that we cannot come up with a cause or explanation for the existence of everything, in the way that we can for the existence of particular things. In any case, I already covered this point several times:

But I would put a caveat there, that the overall context, the Universe, reality, being, or whatever you want to call it. at the limits of both its micro and macro dimensions, obviously cannot be caused by "something else", at least not by something else within the system. — Janus

So whether the Big Bang is uncaused, self-causing, or caused by something unknowable, we are not precluded from conceiving it as an event in terms of its observed consequences. But it can only be understood in terms of its consequences, a fact which itself supports the PSR, it cannot be understood 'in itself'. So, in other words, events like the Big Bang or the decay of uranium atoms are conceivable in terms of their consequences, but not conceivable in themselves. — Janus

So in terms of Frank's 'Big Bang' example, it could be, as he says a brute fact, and will remain so for us, even though it could alternatively be a self-caused, and thus in principle, self-explanatory, event. But confirmation of the latter possibility would seem to be closed to us; we cannot tell whether it is simply a brute fact, is self-caused or even caused by some other set of unknowable conditions. — Janus

Lewisian modal realism dissolves the PSR, in the same way that the guillotine cures a headache. — SophistiCat

Not within this world.

He isn't denying that we believe that nature is ceteris paribus uniform. He is attempting to offer a sufficient reason for that belief. He is being driven by the PSR to do that. If he denied the PSR, he would say our belief requires no explanation.

We look at the past and we assume the future will repeat its past. "From causes which appear similar we expect similar effects. This is the sum of all our experimental conclusions." 4.31

His argument brings into question the uniformity of nature, why should we suspect that nature is ceteris paribus uniform. — Cavacava

Yes, Hume in effect asserts that the PSR is the formulation of human assumptions and may not be true to nature itself; I.e. that it is an epistemological not an ontological principle.

He isn't denying that we believe that nature is ceteris paribus uniform. — frank

Exactly, and it is the very fact that we believe that that shows that we are assuming the PSR, which as you note, Hume himself is also doing in his attempt to explain human nature.

Give me an argument to respond to and I'll consider engaging.

This raises the question whether any one cause could ever be sufficient reason for the existence of anything.

I don't think it matters to the argument whether the PSR is present, as a formulated principle, in the minds of everyday people and scientists; the important point is whether they operate on the implicit understanding that everyday events and the objects of scientific study are capable of explanation. And I think the answer to that question is very obviously 'yes'. — Janus

As I said earlier, this modest observation that we do in fact look for explanations (in the broadest sense of the world) for things is not much of an insight. I mean, what else could we do? How else would we employ our reasoning faculties? It's a banality not worth even talking about, let alone calling it a Principle. And that's not what is usually meant by the PSR.

Your response is very disappointing; you haven't even attempted to address any of the arguments I have made; apparently you would rather try to dismiss what I have said by suggesting it is banal. Cite one philosophical insight that could not possibly be characterized as a banality. The whole enterprise is commonly characterized as banal by those who have no interest in it.

If the PSR is not taken as a Kantian type insight into the fact that objects of knowledge must conform to human reason, then how should it be taken? One alternative would be to take it in the Hegelian manner expressed as " The rational is the real".

If you wanted to argue for the ontological provenance of the PSR, how else would you go about it other than in some variation of a Hegelian/ Spinozist or a Phenomenological/ Heideggerian mode of thought? In other words to merge the epistemological with the ontological or both with the phenomenological. Or some kind of theology perhaps?

Outside of those kinds of approaches is there really anything interesting to talk about at all when it comes to the PSR? All that would seem to be left would be to take a 'shut up and calculate' attitude as science does; an attitude which nonetheless inevitably presupposes the PSR.

What claims do you think are integral to the PSR? What do you mean exactly when you say that we look for explanations "in the broadest sense of the word"? Is that meant to mean that we look for explanations that are less than sufficient? If you do want to say that, then how do you think we would know when any explanation is sufficient? What exactly is it that you want to argue?

Well, in my opinion the PSR is wrong-headed, but specific criticisms need specific examples to which to address them. I don't want to dive into Spinoza, Heidegger or other historical works though, which is why I don't comment on them. I am more interested in live ideas than in philology.

If the PSR is not taken as a Kantian type insight into the fact that objects of knowledge must conform to human reason, then how should it be taken? — Janus

That's not much of an insight. Of course objects of knowledge conform to human reason - they wouldn't be objects of knowledge otherwise.

If you wanted to argue for the ontological provenance of the PSR, how else would you go about it other than in some variation of a Hegelian/ Spinozist or a Phenomenological/ Heideggerian mode of thought? In other words to merge the epistemological with the ontological or both with the phenomenological. Or some kind of theology perhaps? — Janus

Well, let's see how the slogan "Everything must have a sufficient reason" could be cached out.

1. Is it an observation about human reasoning?

1a. We seek reasons and explanations for everything. True, but obvious.

1b. "Objects of knowledge conform to human reason." Not sure what this is doing here, but again, a truism.

1c. We require reasons and explanations for everything. We are not satisfied with brute facts. Things lacking an explanation are unintelligible to us. This, I think, is closer to what some proponents of the PSR say, but as I argued previously, this is not true. The way we actually reason is not at all like this.

2. Is it a regulative principle?

2a. We should seek reasons and explanations for everything. This is a banality.

2b. Objects of knowledge must conform to human reason. Well, they already do.

2c. We must have reasons and explanations for everything. Brute facts are incoherent and unacceptable as objects of knowledge. This is closely related to 1c. Again, I think this is what some proponents of the PSR would say, but I do not agree with this.

3. Is it an ontological principle?

The only ontological formulation that I can think of is something along these lines:

3*. The world is "rational" (perhaps necessarily so): it is such that everything is amenable to explanation. Or, in a more standard form: Nothing can exist unless it has sufficient reasons for its existence and for the way it is.

This can also be seen as a prerequisite for (2c), because without accepting this principle, holding (2c) would be obviously irrational.

Here we should pay closer attention to what is meant by (sufficient) reason, cause or explanation (and the possible differences between these concepts). This is a huge topic, but it cannot be sidestepped in this discussion, because a lot depends on it.

And of course with the ontological formulation, more than with the other two, the obvious question is: Why believe this? Our experience strongly suggests that the world is a pretty orderly place, at least that part of it with which we are familiar. But that observation alone is far too banal to call it a Principle; on the other hand, stronger commitments seem both unwarranted and unnecessary.

3. Is it an ontological principle?

The only ontological formulation that I can think of is something along these lines:

3*. The world is "rational" (perhaps necessarily so): it is such that everything is amenable to explanation. Or, in a more standard form: Nothing can exist unless it has sufficient reasons for its existence and for the way it is. — SophistiCat

It is a physical principle that any finite physical system may be perfectly emulated on a universal computer operating by finite means.

I can't detect any difference between this principle and the ontological formulation of the PSR. Reality is constituted thus.

Of course, in a merely logical sense, it is possible to say that its denial "would state that there is at least one thing that does not have a sufficient reason", but so what? — Janus

This would actually defy the law of identity. If a thing is identifiable as one thing, then there is a reason why it is that thing and not another thing. That's what makes it identifiable as a thing. So you cannot premise that there is one thing which does not have a sufficient reason without saying that this thing is not a thing, and that's contradiction. That it is a thing implies that there is a reason why it is a thing. The PSR cannot be avoided so easily.

You only need one uncaused event to refute PSR. — tom

The same criticism applies to this statement. if it is "one event", as stated, then it is necessarily that event rather than some other event. This implies a reason why it is that event rather than some other event, fulfilling the conditions of the PSR. So rather than refute the PSR such an incident just confirms it.

You ought not confuse "reason" with "cause" unless you are prepared to allow for different types of causes, some non-physical like final causes.

but specific criticisms need specific examples to which to address them — SophistiCat

Yes, and that is precisely what you don't seem to have provided.

I don't want to dive into Spinoza, Heidegger or other historical works though, which is why I don't comment on them. I am more interested in live ideas than in philology. — SophistiCat

Well, we differ here too; for me the ideas of Spinoza, Heidegger, and the rest of the significant thinkers still are as "live" as ever; they form an ineliminable part of philosophy, not merely philology.

That's not much of an insight. Of course objects of knowledge conform to human reason - they wouldn't be objects of knowledge otherwise. — SophistiCat

Yeah, it's easy to say that now...after Kant.

Well, let's see how the slogan "Everything must have a sufficient reason" could be cached out. — SophistiCat

It seems obvious to me that "Everything must have a sufficient reason" can be cashed out in all of the three ways you tried to outline; that is, phenomenologically, ethically and ontologically (the last only provided you don't think as a Cartesian (or a Kantian) dualist, and radically separate thought and being, that is).

We require reasons and explanations for everything. We are not satisfied with brute facts. Things lacking an explanation are unintelligible to us. This, I think, is closer to what some proponents of the PSR say, but as I argued previously, this is not true. The way we actually reason is not at all like this. — SophistiCat

And yet you don't seem to be able to explain how reason is "not at all like this" or give an example of some reasoning which is not like this. So why should I not believe you are indulging in bare assertion?

Here we should pay closer attention to what is meant by (sufficient) reason, cause or explanation (and the possible differences between these concepts). This is a huge topic, but it cannot be sidestepped in this discussion, because a lot depends on it. — SophistiCat

Your allusions to the existence of more exhaustive accounts or counterexamples do not help me; It would be far more helpful if you actually gave some more exhaustive account or counterexample of your own.

And of course with the ontological formulation, more than with the other two, the obvious question is: Why believe this? Our experience strongly suggests that the world is a pretty orderly place, at least that part of it with which we are familiar.But that observation alone is far too banal to call it a Principle; on the other hand, stronger commitments seem both unwarranted and unnecessary. — SophistiCat

As I said before, if we radically separate ontology from human experience and thought, from logic, epistemology and phenomenology, then we have no basis upon which to formulate any ontological or metaphysical principles at all; so the problem then becomes a general one, a problem not confined merely to the PSR.

This would actually defy the law of identity. If a thing is identifiable as one thing, then there is a reason why it is that thing and not another thing. That's what makes it identifiable as a thing. So you cannot premise that there is one thing which does not have a sufficient reason without saying that this thing is not a thing, and that's contradiction. That it is a thing implies that there is a reason why it is a thing. The PSR cannot be avoided so easily. — Metaphysician Undercover

I am sympathetic to your position but not so much to your argument MU. An obvious objection to your argument is that unique sets of qualities are sufficient to differentiate entities from one another, whereas reasons for things possessing those differentiating qualities, need not be known in order to do the differentiating, and it need not even be known that there are such reasons.

Whether or not the reasons are known is irrelevant to the principle of sufficient reason which just states that there is a reason. Whether or not the reason is known is irrelevant. So if there are two entities then they are different from each other, and by the PSR there must be a reason for this. It would make no sense to say that two things are two different things, but there is no reason for this. The very fact that there are (particular) differences is reason for them being (in general) different. So the reason for them being two distinct things is the difference between them.

In this example it makes no difference whether the actual difference (which is the reason for them being different) is known, because the example stipulates that they are different. Therefore by the stipulation of the example, and the PSR, there must be a difference between them (the reason for them being different things), regardless of whether the difference is known, and this difference is the reason why we can say that they are different. If there were no difference between them, they would not be two different things

I'm not really following you. If you didn't know the reasons for two things being different, then how could you know there are such reasons? Would this not be an unjustified assumption?

Or are you proposing a more deflationary approach which might, for example, count the very having of different qualities as sufficient reason for things being different from one another?

I'm not really following you. If you didn't know the reasons for two things being different, then how could you know there are such reasons? Would this not be an unjustified assumption? — Janus

It's simple logic. In order that they are different, there must be a difference. The difference is the reason why they are different. That they are not the same (different) requires, logically, that there is a difference.

Or are you proposing a more deflationary approach which might, for example, count the very having of different qualities as sufficient reason for things being different from one another? — Janus

It's not even necessarily a matter of having distinct qualities, it's simply a matter of difference. Remember, we are starting from the other side, assuming that two things are different things. This doesn't necessitate specifically that they have distinct qualities, as the reason for being different, it just necessitates a difference between them.

Seeing as your responses have degenerated into hostile retorts, I don't know if it is worth continuing this conversation. But I'll give it another try.

We require reasons and explanations for everything. We are not satisfied with brute facts. Things lacking an explanation are unintelligible to us. — SophistiCat

And yet you don't seem to be able to explain how reason is "not at all like this" or give an example of some reasoning which is not like this. So why should I not believe you are indulging in bare assertion? — Janus

As I said, I discussed this in my preceding posts. The context in which the "rationality" of the world or the acceptability and intelligibility of brute facts show up is pretty much limited to a line of philosophical questioning in the mode of the PSR - and here, of course, opinions differ. By contrast, in our ordinary and scientific reasoning such questions are largely irrelevant. We deal with a world that is partially intelligible, as far as we are concerned, we deal with it piecemeal, and we seem to do fine that way. Our inquiries seek to illuminate some regularities and connections, which abut on assumptions and probabilities that are not themselves accounted for within the context of the inquiry. Any such inquiry leaves out of its scope the vast majority of the world, which, for all it matters, could be shrouded in darkness. And this limited comprehension is what we usually understand by explaining, finding causes and reasons. We do not require the world to be totally rational and noncontingent before we can say that we understand something about it.

My conclusion is that the PSR cannot claim to be a phenomenological principle that faithfully captures the way we actually reason.

Your allusions to the existence of more exhaustive accounts or counterexamples do not help me; It would be far more helpful if you actually gave some more exhaustive account or counterexample of your own. — Janus

I wasn't alluding to counterexamples. My point was that words such as "reason," "cause" or "explanation" are too controversial to be employed in a thesis without unpacking their meaning. I have discussed the way I believe we actually reason, but I am not the one advancing a PSR thesis. It is up to a PSR proponent to explain what they mean, and why.

I have pointed out how our actual reasoning is not nearly as comprehensive as an unrestricted PSR suggests. Another important question to consider is how subjective it is: how much of the perceived "rationality" of the world is in our heads, vs. being a direct impression of the way the world actually is. I think there is some of both. On the PSR-friendly side of the dilemma, our very existence and our rational faculties seem to require an objectively regular environment. But on the other side, the multiplicity of working accounts of the world casts doubt on the idea that there must be a unique, objective and comprehensive Reason for everything.

Just one small but illustrative example: anthropic explanations in fundamental physics and cosmology. Briefly, the trajectory of physical and cosmological theories typically leads scientists towards mathematical models that are themselves taken to be the brute facts of reality - albeit with a hope held out for their reduction to an even more accurate and comprehensive system of mathematical structures and constants as science progresses. However, a radically different explanatory terminus has been suggested in the latter half of the last century (if not earlier): our very existence as "observers," living creatures with the ability to make observations and come up with such theories - a Cartesian turn, if you like. (Fred Hoyle's prediction of a hitherto unknown quantum state in carbon-12 is often cited as an example of anthropic reasoning, although this interpretation is disputed.) You may have also heard about so-called fine-tuning of the fundamental constants: the constants "had to be" within such-and such narrow range in order for the universe to be able to produce and support living creatures like us. Not everyone likes this anthropocentric framing, but it does have some appeal, even if we are trying to be objective about it: after all, our own existence is the one thing that we can believe with more confidence than anything else! Why not this as at least one of the reasons?

Seeing as your responses have degenerated into hostile retorts, I don't know if it is worth continuing this conversation. But I'll give it another try. — SophistiCat

I honestly don't know what gave you the idea that my responses have become "hostile". That seems to be an overreaction; maybe there is a tinge of frustration or impatience in them, I guess...I don't know...

By contrast, in our ordinary and scientific reasoning such questions are largely irrelevant. — SophistiCat

But all this says is that everyday people and scientists are not necessarily doing philosophy; which is of course, obviously true but, I would still say, irrelevant. The fact that the world is always only partially intelligible is also irrelevant, as I see it, because the PSR expresses the fact that, in all our enquiries and fields, we are not satisfied with partial or insufficient understanding and are constantly seeking ever more sufficient explanations, with the obvious caveat that we can never know when any explanation is finally and absolutely sufficient.

So, my conclusion is that the PSR does capture the phenomenology of human knowledge-seeking, insofar as we are never, generally speaking, satisfied with the current sufficiency of our knowledge and reasoning, and are constantly seeking to increase it. If all you want to claim against the PSR is that there can be no, for us, absolutely sufficient explanation, and that our enquiries don't necessarily need to proceed on the assumption that there is such an absolute explanation, then perhaps we have not been disagreeing so much after all.

Another important question to consider is how subjective it is: how much of the perceived "rationality" of the world is in our heads, vs. being a direct impression of the way the world actually is. I think there is some of both. On the PSR-friendly side of the dilemma, our very existence and our rational faculties seem to require an objectively regular environment. But on the other side, the multiplicity of working accounts of the world casts doubt on the idea that there must be a unique, objective and comprehensive Reason for everything. — SophistiCat

This is where we diverge, I think. You seem to have a kind of Cartesian view which separates the subject from the world such that rationality could be 'merely in our heads", and that the world could somehow "be some way" that is radically different from the way we experience it. Also, the PSR does not require that there be a "unique, objective and comprehensive Reason for everything", but merely that nothing happens in our world without sufficient reason or cause.

Just one small but illustrative example: anthropic explanations in fundamental physics and cosmology. — SophistiCat

Not everyone likes this anthropocentric framing, but it does have some appeal, even if we are trying to be objective about it: after all, our own existence is the one thing that we can believe with more confidence than anything else! Why not this as at least one of the reasons? — SophistiCat

However, a radically different explanatory terminus has been suggested in the latter half of the last century (if not earlier): our very existence as "observers," living creatures with the ability to make observations and come up with such theories - a Cartesian turn, if you like. Not everyone likes this anthropocentric framing, but it does have some appeal, even if we are trying to be objective about it: after all, our own existence is the one thing that we can believe with more confidence than anything else! Why not this as at least one of the reasons? — SophistiCat

I wouldn't call this a Cartesian turn, but quite the opposite, a somewhat Kantian or phenomenological turn that heralds the closing of the Cartesian gap between mind and world. And I totally agree; "why not this as at least one of the reasons"? That's what I alluded to earlier; there is no radical separation between us and the world, between our rationality and the 'way things are'. Of course anthropomorphizing can get out of hand, but we need not be ashamed that our views are, as they inevitably must be, anthropocentric; the world must be 'human-shaped' for us, and this is exactly the same as to say that our objects of knowledge must conform to human reason, as we discussed earlier. Then you said that observation is trivially and obviously true and yet those who do not like "this anthropocentric framing" apparently would beg to differ; it would seem that they, at least, cannot see what is so trivially and obviously true.

So their difference is sufficient reason for their being different? Alrighty then...

Do you notice that the particular, the specific difference, is distinct from the general, being different?

The turn is quite Cartesian in that it is about securing the world we know. One of Descartes major moves is to arrive at a conclusion our understandings amount to knowledge.

In thus respect, Descartes shares a similarly with Kant. Both are positioned against those who would argue our experiences are somehow deficient in reporting what is happening. Descartes doesn't have the strict seperation between mind and body that a lot of people attribute to him. For him, experiences are not somehow incompatible or a non-relation to bodies. In many senses, they are mixed up in relation-- hence he's able to talk about what we can understand in relation to bodies that are present.

Rigjt, so the particular difference is sufficient reason for the general condition of being different?

When I say "Cartesian" I am referring to how that is usually understood and characterized. Whether Descartes was himself really Cartesian is a question I am not sufficiently knowledgeable about or interested in to offer an opinion.

So, my conclusion is that the PSR does capture the phenomenology of human knowledge-seeking, insofar as we are never, generally speaking, satisfied with the current sufficiency of our knowledge and reasoning, and are constantly seeking to increase it. If all you want to claim against the PSR is that there can be no, for us, absolutely sufficient explanation, and that our enquiries don't necessarily need to proceed on the assumption that there is such an absolute explanation, then perhaps we have not been disagreeing so much after all. — Janus

No disagreement here, but, as I keep saying, this is too weak to even be called a Principle, and doesn't really sound like the PSR in Leibnitz's or Scholastic tradition, which, as I understand it, requires the world to be objectively "rational" through and through.

Also, the PSR does not require that there be a "unique, objective and comprehensive Reason for everything", but merely that nothing happens in our world without sufficient reason or cause. — Janus

Ah, but here you are making a much stronger statement. This is no longer just about our knowledge-seeking, isn't it?

This is where we diverge, I think. You seem to have a kind of Cartesian view which separates the subject from the world such that rationality could be 'merely in our heads", and that the world could somehow "be some way" that is radically different from the way we experience it. — Janus

Well, what would be the alternative? Remember, the very framing of this conversation presupposes, for good or ill, subjects and objects: things in the world and our explanations, reasons, causes, which are about those things.

I wouldn't call this a Cartesian turn, but quite the opposite, a somewhat Kantian or phenomenological turn that heralds the closing of the Cartesian gap between mind and world. — Janus

I meant "Cartesian" in its method: start with the one idea that you cannot possibly deny, put it at the center of your explanatory scheme.

And I totally agree; "why not this as at least one of the reasons"? That's what I alluded to earlier; there is no radical separation between us and the world, between our rationality and the 'way things are'. — Janus

I don't think you understood the point of my example, which was to show how, even in the most rationalistic projects of fundamental science, once we start pushing against the limits of our modeling, not only do we have to concede that there are brute facts, explanatory termini that admit no further explanation, but that there isn't even a unique, rational choice to be made about what those brute facts should be. Some may prefer to put just physical laws and constants at the foundation of the reductive scheme, while others may argue, not without reason, that those laws and constants can be further reduced/constrained if we take the existence of observers as one of the givens. (And if Apo was here, he would, of course, be pushing for other high-level constraints as yet another alternative set of brute facts.)