The deductive-nomological model (DN model)... is a formal view of scientifically answering questions asking, "Why...?". The DN model poses scientific explanation as a deductive structure—that is, one where truth of its premises entails truth of its conclusion—hinged on accurate prediction or postdiction of the phenomenon to be explained. — Wiki
According to Hempel, an explanation is:
...an argument to the effect that the phenomenon to be explained ...was to be expected in virtue of certain explanatory facts. (1965 p. 336) — IEP
We can find the "cash value" in this idea by noting that it is useful to "throw away" information sometimes in order to deduce that which is to be expected -- or to explain what was observed. The veil that is stripped is just everything in the totality that isn't relevant to our purpose. The face beneath the veil would be a "skeleton" of postulated necessities that we might in theory use to reconstruct the veil, given some initial conditions.Duhem claimed that:
To explain is to strip the reality of the appearances covering it like a veil, in order to see the bare reality itself. (op.cit.: p19) — IEP
Things are explained by pointing to the constraints that bound possibility. — apokrisis
Then of course Aristotle came up with four kinds of "becauses". We can say a horse is what it is because of the specific constraints in terms of what it is made of, how it came to be made, for what reason it was made, and with what design it was made. — apokrisis
This still seems like the postulation of necessity. Horsesmust be within specific constraints. Our postulates become more specific. But how does one avoid a "If x then y" as a premise from which y can be deduced in the context of x? — Hoo
I like this. I don't see how we could know that we have the "actually naturally necessary," but I can see that we can and do act successfully as if. I see a spectrum of intensisty. On one side the postulated necessity is just acted upon as necessity in deed. The other side is tentative, the cutting edge of the imagination.So horse becomes nothing but a state of constraint. It is constraints all the way down. But now we must realise how out of pure epistemic blinkeredness, we often class accidental constraints along with the actually naturally necessary. Or indeed, vice versa. — apokrisis
I think this analysis of the horse is the other side of the question, which I've neglected. We need x and y before we can postulate necessity. And perhaps we can view x and y as unstable systems of constraints. Change one entity in the same and you change them all. — Hoo
Something I didn't mention in the OP was the postulation of unseen entities. That's very important. But I thought I'd focus on the "projection" of necessity. Of course the assumed uniformity of nature figures into this. — Hoo
OK, but will there be assumed uniformity of nature in 5 minutes? — Hoo
https://www.princeton.edu/~grosen/puc/phi203/induction.htmlSuppose that Hume is right about how we actually think. So far all we have is a fact about human cognitive psychology. And this fact, however interesting, does not settle the normative question: Is it legitimate for us to proceed in this way? Are the conclusions we reach as a result of inductive inference really justified?
A first pass suggests a negative answer. After all, the inference pattern
(DATA) In my experience, all Fs are Gs
(THEORY) Therefore, in general all Fs are Gs, (or at least, the next F I examine will be G).
is not deductively valid. It is logically possible for the conclusion to be false when the premise is true. So a skeptic might say: In so-called inductive reasoning, human beings commit a fallacy. They accept a general proposition on the basis of an invalid argument. And this means that their acceptance of that general proposition is unjustified.
Now this is not exactly Hume's way of raising skeptical worries. Hume rather takes the invalidity of the inference from DATA to THEORY as evidence that we have failed to make our method fully explicit. That we unheasitatingly pass from DATA to THEORY shows that we accept a principle connecting the two, a principle that normally passes unnoticed because we take it so completely for granted, but which figures implicitly in every instance of inductive reasoning.
Hume formulates this missing premise as the claim that the future will resemble the past. But for our purposes it will be useful to work with a somewhat more precise formulation. What we need to make the inverence from DATA to THEORY valid is a premise of the form:
(UN) For the most part, if a regularity R (e.g., All Fs are Gs) holds in my experience, then it holds in nature generally, or at least in the next instance.
"UN" stands for the "Uniformity of Nature". This is a traditional (post-Humean) label for the missing premise, though in fact it is misleading. For UN is not simply the claim that nature exhibits regularities. It is the claim that the regularities that have emerged in my experience are among the regularities that hold throughout nature. It might better be called a principle or representativeness, for its central message is that my experience, though limited in time and space to a tiny fraction of the universe, is nonetheless a representative sample of the universe.
The inference from DATA + UN to THEORY is valid. Moreover, there is no question for now about our right to accept the DATA. So if we want to know whether we ever have a right to accept a generalization like THEORY, we must ask whether we have reason to believe UN. — link below
Now I suspect you will argue around this via Popper. But I wonder if the assumption UN isn't going to be hiding somewhere. I like the notion that the mind is an expectation machine and that violations of expectation in particular come to our attention. We expect the future to resemble the past — Hoo
"UN" stands for the "Uniformity of Nature". This is a traditional (post-Humean) label for the missing premise, though in fact it is misleading. For UN is not simply the claim that nature exhibits regularities. It is the claim that the regularities that have emerged in my experience are among the regularities that hold throughout nature. — link below
So, you have completely abandoned the idea of explanation. That's a shame. — tom
Theories (postulations of necessity that allow for the generations of implications that can be falsified) are seemingly going to be stronger and more falsifiable as they are projected across time and space.Popper coined the term "critical rationalism" to describe his philosophy. Concerning the method of science, the term indicates his rejection of classical empiricism, and the classical observationalist-inductivist account of science that had grown out of it. Popper argued strongly against the latter, holding that scientific theories are abstract in nature, and can be tested only indirectly, by reference to their implications. He also held that scientific theory, and human knowledge generally, is irreducibly conjectural or hypothetical, and is generated by the creative imagination to solve problems that have arisen in specific historico-cultural settings. — W
This is also my starting point.Popper and David Hume agreed that there is often a psychological belief that the sun will rise tomorrow, but both denied that there is logical justification for the supposition that it will, simply because it always has in the past. Popper writes, "I approached the problem of induction through Hume. Hume, I felt, was perfectly right in pointing out that induction cannot be logically justified." (Conjectures and Refutations, p. 55) — W
This "probability" seems to reduce to economy. Popper prefers more uniformity. Hence it is "irrational" to project "extra conditions." He tries to milk this from convenience of falsification (ease of attack.) But of course we also want a stronger theory for its greater utility (we want our technology to work everywhere and everywhen.) As far as the use of PUN, it looks to be at the heart of any theory worth suggesting. If we can't infer from the past and present to the future, we are lost. We trust theories because they have worked for us and because we assume that this utility will continue. WhNor is it rational according to Popper to make instead the more complex assumption that the sun will rise until a given day, but will stop doing so the day after, or similar statements with additional conditions.
Such a theory would be true with higher probability, because it cannot be attacked so easily: to falsify the first one, it is sufficient to find that the sun has stopped rising; to falsify the second one, one additionally needs the assumption that the given day has not yet been reached. — W
I think the DN model is more or less what I'm defending, thoughI'm looking at it in a broader context than physical science. We have a "folk science" of human nature that we use to navigate social situations, for instance. And metaphysicians also seem to explain things this way or mean something like this by "explanation." — Hoo
UN is one of the fundamental misconceptions of inductivism. It is a principle in that no one has ever been able to properly formulate, beyond vague notions such as "the future will resemble the past" or "the seen resembles the unseen". Your suggestion that it might be formulated "the regularities of experience are universal regularities"? — tom
The thesis is that explanation of X is deduction of X from postulated necessity. Now this postulation is the creative act, the myth or element of rationalism. — Hoo
Theories (postulations of necessity that allow for the generations of implications that can be falsified) are seemingly going to be stronger and more falsifiable as they are projected across time and space. — Hoo
This "probability" seems to reduce to economy. — Hoo
That is utterly incompatible with the assumption of the Principle of the Uniformity of Nature, and what you were claiming about inducing THEORY from DATA, which is impossible. — tom
I recall well how the key ideas of my idealistic theory of natural laws - of “lawfulness as imputation” - came to me in 1968 during work on this project while awaiting the delivery of Arabic manuscripts in the Oriental Reading Room of the British Museum. It struck me that what a law states is a mere generalization, but what marks this generalization as something special in our sight -- and renders it something we see as a genuine law of nature -- is the role that we assign to it in inference. Lawfulness is thus not a matter of what the law-statement says, but how it is used in the systematization of knowledge -- the sort of role we impute to it. These ideas provided an impetus to idealist lines of thought and marked the onset of my commitment to a philosophical idealism which teaches that the mind is itself involved in the conceptual constitution of the objects of our knowledge. (Instructive Journey: An Essay in Autobiography, pages 172-173) — Rescher
I'm going to quibble about your thesis. A scientific theory *is* a conjectured explanation of some aspect of reality - the explicanda of the theory. The explanation takes the form of a statement of what exists in reality, how it behaves, and how it accounts for the explicanda. So yes, the eXplicanda can be deduced from the claim about what exists in reality, but what is this "postulated necessity"? — tom
I just assumed you were into the falsifiability criterion, with your talk of Popper turning in his grave. I'd say that the epistmology we live by is "irrational" in the sense that it is shaped by pleasure and pain as as consequence of acting as if a given myth is true. Beliefs (postulated necessities, expectations) are "falsified" when they lead to pain and failure. There is also the pleasure of coherence and the pain of cognitive dissonance, so we can sit in an armchair and "improve" our belief system. Call it "radical instrumentalism." Systems of beliefs as a whole are tools in the "hands" of "irrational" feeling. From this perspective, philosophy of science is largely just a "false" foundation, since I think the prestige of science mostly rests on its technological "miracles." Similarly, real analysis can be described as tidying up the cognitive dissonance of a calculus that was already working to satisfy less abstract desires.There is no such thing as an experimental test that can logically falsify a theory, if that is what you mean. — tom
Perhaps according to your definition thereof. I think we can project constrains on the future, fit probability densities to data, etc.You can't use probability calculus with explanations. — tom
I bring this up all the time--that it's often not clear what someone is asking for in requesting an explanation, or why what they're asking for should count as an explanation, or why it should exhaust what can count as an explanation. — Terrapin Station
We can find the "cash value" in this idea by noting that it is useful to "throw away" information sometimes in order to deduce that which is to be expected -- or to explain what was observed. The veil that is stripped is just everything in the totality that isn't relevant to our purpose. The face beneath the veil would be a "skeleton" of postulated necessities that we might in theory use to reconstruct the veil, given some initial conditions. — Hoo
It seems to me that the "totality" must remain unexplained, at least if my concept of explanation is intended. — Hoo
Science cannot solve the ultimate mystery of nature. And that is because, in the last analysis, we ourselves are a part of the mystery that we are trying to solve. — Max Planck
But if you start to ask 'why those principles' or 'why do Newton's laws obtain and not some other laws', then I think you're going beyond the bounds of what might reasonably be explained. — Wayfarer
We try to contemplate the totality, but that is exactly like trying to see it from the outside. — Hoo
I just assumed you were into the falsifiability criterion, with your talk of Popper turning in his grave. — Hoo
I once had the idea 'you couldn't have a "theory of everything" because "the theory" would have to be included in the "everything" that is the subject of the explanation'. So there would always be a problem of recursiveness, that your explanation includes the explainer. And that seems very close to what Planck was driving at. — Wayfarer
To be sure, in the end, “scientific knowledge” comes back toward itself and reveals itself to itself: its final goal is to describe itself in its nature, in its genesis, and in its development.
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It is by following this “dialectical movement” of the Real that Knowledge is present at its own birth and contemplates its own evolution. And thus it finally attains its end, which is the adequate and complete understanding of itself — i.e., of the progressive revelation of the Real and of Being by Speech — of the Real and Being which engender, in and by their “dialectical movement,” the Speech that reveals them.
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Taken separately, the Subject and the Object are abstractions that have neither “objective reality” (Wirklichkeit) nor “empirical existence” (Dasein). What exists in reality, as soon as there is a Reality of which one speaks — and since we in fact speak of reality, there can be for us only Reality of which one speaks what exists in reality, I say, is the Subject that knows the Object, or, what is the same thing, the Object known by the Subject.
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The concrete Real (of which we speak) is both Real revealed by a discourse, and Discourse revealing a real. And the Hegelian experience is related neither to the Real nor to Discourse taken separately, but to their indissoluble unity. And since it is itself a revealing Discourse, it is itself an aspect of the concrete Real which it describes. It therefore brings in nothing from outside, and the thought or the discourse which is born from it is not a reflection on the Real: the Real itself is what reflects itself or is reflected in the discourse or as thought.
— Kojeve
At issue is this: that naturalism must 'assume the subject'. In other words, naturalism assumes, or begins from, the fact of the intelligent subject in the domain of objects and forces.
But that only succeeds in 'burying the metaphysics', so to speak - denying that there is any metaphysic, whilst actually being embedded in one (for which, see 'the spirituality of secularity', on pages 189-190 of this essay). — Wayfarer
I don't think we can condemn modernity but only the shallow understandings of the metaphysical/spiritual import of the scientific image — Hoo
I think we agree on our dismissal of scientism as an option, at least as a personal adjustment. I think we both have access to different non-scientific traditions that sustain us.I had the idea this is what the thread was about. — Wayfarer
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