The so-called "scientific method" is, I think, rather poorly understood. For example, let us consider one of the best-known laws of nature, often simply referred to as the Law of Gravity:
Newton's Law of Universal Gravitation: Every object in the universe attracts every other object toward it with a force proportional to the product of their masses, divided by the square of the distance between their centers of mass.
Now here is a series of questions for you, which I often ask audiences when I give lectures on the philosophy of science:
- Do you believe Newton's Law of Universal Gravitation is true?
- If so, how sure are you that it is true?
- Why do you believe it, with that degree of certainty?
The most common answers to these questions are "yes", "very sure", and "because it has been extensively experimentally verified." Those answers sound reasonable to any child of the Enlightenment -- but I submit, on the contrary, that this set of answers has no objective basis whatsoever. To begin with, let us ask, how many confirming experiments do you think would have been done, to qualify as "extensive experimental verification." I would ask that you, the reader, actually pick a number as a rough, round guess.
Whatever number N you picked, I now challenge you state the rule of inference that allows you to conclude, from N uniform observations, that a given effect is always about from a given alleged cause. If you dust off your stats book and thumb through it, you will find no such rule of inference rule there. What you will find are principles that allow you to conclude from a certain number N of observations that with confidence c, the proportion of positive cases is z, where c < 1 and z < 1. But there is no finite number of observations that would justify, with any nonzero confidence, that any law held universally, without exception (that is, z can never be 1 for any finite number of observations, no matter how small the desired confidence c is, unless c = 0). . And isn't that exactly what laws of nature are supposed to do? For Pete's sake it is called the law of universal gravitation, and it begins with the universal quantifier every (both of which may have seemed pretty innocuous up until now).
Let me repeat myself for clarity: I am not saying that there is no statistical law that would allow you to conclude the law with absolute certainty; absolute certainty is not even on the table. I am saying that there is no statistical law that would justify belief in the law of universal gravitation with even one tenth of one percent of one percent confidence, based on any finite number of observations. My point is that the laws of the physical sciences -- laws like the Ideal gas laws, the laws of gravity, Ohm's law, etc. -- are not based on statistical reasoning and could never be based on statistical reasoning, if they are supposed, with any confidence whatsoever, to hold universally.
So, if the scientific method is not based on the laws of statistics, what is it based on? In fact it is based on the
Principle of Abductive Inference: Given general principle as a hypothesis, if we have tried to experimentally disprove the hypothesis, with no disconfirming experiments, then we may infer that it is likely to be true -- with confidence justified by the ingenuity and diligence that has been exercised in attempting to disprove it.
In layman's terms, if we have tried to find and/or manufacture counterexamples to a hypothesis, extensively and cleverly, and found none, then we should be surprised if we then find a counterexample by accident. That is the essence of the scientific method that underpins most of the corpus of the physical sciences. Note that it is not statistical in nature. The methods of statistics are very different, in that they rest on theorems that justify confidence in those methods, under assumptions corresponding to the premises of the theorems. There is no such theorem for the Principle of Abductive Inference -- nor will there ever be, because, in fact, for reasons I will explain below, it is a miracle that the scientific method works (if it works).
Why would it take a miracle for the scientific method to work? Remember that the confidence with which we are entitled to infer a natural law is a function of the capability and diligence we have exercised in trying to disprove it. Thus, to conclude a general law with some moderate degree of confidence (say, 75%), we must have done due diligence in trying to disprove it, to the degree necessary to justify that level confidence, given the complexity of the system under study. But what in the world entitles us to think that the source code of the universe is so neat and simple, and its human denizens so smart, that we are capable of the diligence that is due?
For an illuminating analogy, consider that software testing is a process of experimentation that is closely analogous to scientific experimentation. In the case of software testing, the hypothesis being tested -- the general law that we are attempting to disconfirm -- is that a given program satisfies its specification for all inputs. Now do you suppose that we could effectively debug Microsoft Office, or gain justified confidence in its correctness with respect to on item of its specification, by letting a weasel crawl around on the keyboard while the software is running, and observing the results? Of course not: the program is far too complex, its behavior too nuanced, and the weasel too dimwitted (no offense to weasels) for that. Now, do you expect the source code of the Universe itself to be simpler and friendlier to the human brain than the source code of MS Office is to the brain of a weasel? That would be a miraculous thing to expect, for the following reason: a priori, if the complexity of that source code could be arbitrarily large. It could be a googleplex lines of spaghetti code -- and that would be a infinitesimally small level of complexity, given the realm of possible complexities -- namely the right-hand side of the number line.
In this light, if the human brain is better equipped to discover the laws of nature than a weasel is to confidently establish the correctness an item in the spec of MS Office, it would be a stunning coincidence. That is looking at it from the side of the a priori expected complexity of the problem, compared to any finite being's ability to solve it. But there is another side to look from, which is the side of the distribution of intelligence levels of the potential problem-solvers themselves. Obviously, a paramecium, for example, is not equipped to discover the laws of physics. Nor is an octopus, nor a turtle, nor a panther, nor an orangutan. In the spectrum of natural intelligences we know of, it just so happens that there is exactly one kind of creature that just barely has the capacity to uncover the laws of nature. It is as if some cosmic Dungeon Master was optimizing the problem from both sides, by making the source code of the universe just simple enough that the smartest beings within it (that we know of) were just barely capable of solving the puzzle. That is just the goldilocks situation that good DM's try to achieve with their puzzles: not so hard they can't be solved, not so easy that the players can't take pride in solving them
There is a salient counterargument I must respond to. It might be argued that, while it is a priori unlikely that any finite being would be capable of profitably employing the scientific method in a randomly constructed universe, it might be claimed that in hindsight of the scientific method having worked for us in this particular universe, we are now entitled, a posteriori, to embrace the Principle of Abductive Inference as a reliable method. My response is that we have no objective reason whatsoever to believe the scientific method has worked in hindsight -- at least not for the purpose of discovering universal laws of nature! I will grant that we have had pretty good luck with science-based engineering in the tiny little spec of the universe observable to us. I will even grant that this justifies the continued use of engineering for practical purposes with relative confidence -- under the laws of statistics, so long as, say, one anomaly per hundred thousand hours of use is an acceptable risk. But this gives no objective reason whatsoever (again under the laws of statistics) to believe that any of the alleged "laws of nature" we talk about is actually a universal law. That is to say, if you believe, with even one percent confidence, that we ever have, or ever will, uncover a single line of the source code of the universe -- a single law of Nature that holds without exception -- then you, my friend, believe in miracles. There is no reason to expect the scientific method to work, and good reason to expect it not to work -- unless human mind was designed to be able to uncover and understand the laws of nature, by Someone who knew exactly how complex they are.
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Notes -
So not the classical, but the non-classical modern sense.
Classicism in truth theories usually refers to the division between theories that rely on criteria and procedures and theories that do not.
Evidence theory (A is true if A is evident), coherence theory (A is true if it can be embedded in a coherent system without destroying its coherence), common agreement theory (A is true if specialists agree about its correctness), utilitarian theory (A is true if A is useful); these are all non-classical theories because they appeal to a mechanism to obtain truth.
Classical theories do not do this, and consider true what is necessarily so without appealing to criteria.
For instance Tarski's STT that works through a relation of satisfaction and solely operates on formal languages is a classical theory of truth in the line of the Aristotelian syllogisms that it was inspired by.
"aliens exist" is a classically meaningless statement because you neither defined what an alien is nor the totality of an existence relationship.
Logical necessities. Anything that isn't contingent on evidence and stands by itself. Things that are so by virtue of pure reason, before evaluation of the senses. Things that are true a priori.
Most of mathematics is true in this strict sense, none of science is.
Ok, I was going for a plain language simple answer, but you obviously know your stuff. Tarski's STT in the Popper/Miller interpretation is the theory of truth I adhere to, then.
I see. OP seems to be arguing absolutes, so probabilistic epistemologies are going to be hard to reconcile, but I think I understand your point better with that added context.
I think you're right to say that it's not necessary that theories of our observations that don't assume a metaphysics are fictitious. And Propensity is a good example of this.
But one can probably retort that in application even such theories have to make the assumption that the universe is meaningfully descriptible, a fortiori probabilistically, if they want to make a claim at Truth. Which as I understand is the whole debate around inductive skepticism.
I've never found Popper's arguments to the abilities of pure deductivism to be entirely convincing myself. Even he has to appeal to one hypothesis being better or worse “corroborated” by the evidence which decays him into method. Hence the unfortunate fate of logical positivism.
I'm not sure I can follow everything you're saying here, but I'm interested in what you find unconvincing about Popper, if you feel like expounding on it. I hope you're not implying Popper was a logical positivist :)
It would be a bit silly to say that about one of its most tenacious critics. I'm merely saying his own criticisms of the problems with induction apply to his own ideas when scrutinized. He's a deductivist in the same way Marx is a materialist: only in theory.
I really have two problems with Popper.
First, the aforementioned issue with deductivism requiring some ranking of theories through experimentation.
I think this reintroduces the problems he sees in positivism.
The way he tries to get away with it is, as you know, by refraining from claiming truth and instead having science go for truthlikeness and verisimilitude.
This is all well and good and a more honest account of the scientific process, but his definition of truthlikeness is incoherent (by his own estimation) because it can't rank false theories. We may yet find a satisfactory solution for this but none of the attempts I've seen were very convincing.
Second is the more mundane criticism that his views don't manage to characterize a lot of behavior that we do regard as scientific. There is a lot wrong with Khune bun on this I wager he is correct.
Whew, you wouldn't believe the amount of times I've hear the "Popper is a positivist" claim. From Stephen Hawking, for instance. I don't mean that as an indictment of the person making the claim, really, I mean you don't have to know everything, but of the secondary sources who taught people wrong.
Popper does claim truth for his theories though, in the sense of theories being true through correspondence with reality, but without us being able to know whether they are true. I agree that while interesting, verisimillitude never managed to be very clear or coherent, though. But his basic "logic of scientific discovery" does not rely on it.
There's an interesting bit in Popper's Realism and the Aim of Science on Khun, where Popper basically says he has no problem with Khun (or at least a non-relativist reading of him) and that Khun done good work on describing the scientific process, but that this doesn't really clash with Popper's views.
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