Wittgenstein had taken the position regarding “philosophical or metaphysical propositions: that they were senseless or meaningless”. In order to characterize science as opposed to philosophy,
“…the propositions which belong to science are those deductible from true observation statements; they are those propositions which can be verified by true observation statements. Could we know all the true observation statements, we should also know the all that may be asserted by natural science. This amounts to a crude verifiability criterion of demarcation.”[emphasis in original]Popper realized that this approach had several flaws, including the Inductive issue, and the issue of “meaning”. Popper states:
”No scientific theory can be deduced from observation statements, or be described as a truth function of observation statements.”He presented his ideas to the Vienna Circle in 1931/2. In 1933, he submitted his ideas to Erkentnnis. Because they were misunderstood for a while, his ideas created intellectual turbulence and criticism.
Popper agreed with Hume:
”Hume, I felt, was perfectly right in pointing out that induction cannot be logically justified. He held that there can be no valid logical arguments allowing us to establish…Popper released his book, “The Logic of Scientific Discovery” in 1935, republished in 1959, 1992, 2002, 2004, 2006. In this, he defines knowledge thus:
‘that those instances, of which we have had no experience, resemble those of which we have had experience. [consequently] even after the observation of the frequent or constant conjunction of objects, we have no reason to draw any inference concerning any objet beyond those of which we have had experience. For ‘shou’d it be said that we have experience’ … ‘then I wou’d renew my question, why from this experience we form any conclusion beyond the past instances, of which we have had experience.’This ‘renewed question’ indicates that an attempt to justify the practice of induction by an appeal to experience must lead to an infinite regress.”
”The theory of knowledge, whose task is the analysis of the method or procedure peculiar to empirical science, may accordingly be described as a theory of the empirical method – a theory which is usually called ‘experience’.”Immediately after defining knowledge, Popper explains demarcation:
[emphasis in original]
”The criterion of demarcation inherent in inductive logic – that is, the positivist dogma of meaning – is equivalent to the requirement that all the statements of the empirical science (or all ‘meaningful statements’) must be capable of being finally decided, with respect to their truths and falsity; we shall say that they must be ’conclusively decidable’. This means that their form must be such that to verify them and to falsify them must both be logically possible.”In other words, if it is not both verifiable AND falsifiable, then it cannot lead to knowledge or truth.
[emphasis in original]
Later in the book, Popper addresses the concept of “corroboration” and “corroborability”, which also directly relate to the generation of actual knowledge:
”…it is not so much the number of corroborating instances which determines the degree of corroboration, but the severity of the various tests" to which the hypothesis can be, and has been, subjected. But the severity of the tests, in its turn, depends upon the degree of testability and thus upon the simplicity of the hypothesis: the hypothesis which is falsifiable in a higher degree, or the simpler hypothesis, is also the one which is corroborable in a higher degree.[7.]The injection of probability theory into the search for knowledge also is dealt with by Popper, thus:
”Most of those who believe in probability logic uphold the view that the appraisal is arrived at by the means of a ‘principle of induction’ which ascribes the probabilities to the induced hypotheses. But if they ascribe a probability to this principle of induction in its turn, then the infinite regress continues If on the other hand they ascribe ‘truth’ to it then they are left with the choice between infinite regress and a priorism. ‘Once and for all’, says Heymans, ‘ the theory of probability is incapable of explaining inductive arguments; for precisely the sae problem which lurks in one also lurks in the other (in the empirical application of probability theory).”In applying all this to evolution, Popper wrote in 1945, regarding Karl Marx:
[emphasis in original]
”Marx may be excused for holding the mistaken belief that there is a ‘natural law of historical development’; for some of the best scientists of his time (e.g. T. H. Huxley….) believed in the possibility of discovering a law of evolution. But there can be no empirical ‘law of evolution’. [emphasis added here only] There is a specific hypothesis of evolution, stating that life on earth has developed in certain ways. But a universal or natural law would have to state a hypothesis concerning the course of development of life on all planets (at least). In other words,, wherever we are confined to the observation of one unique process, there we cannot hope to find, and to test, a ‘law of nature’.”To this point in his thoughts, Popper has been consistent. Knowledge requires testing for verification and falsification; induction fails, even with probability added. And by now we realize that there are two aspects to Popperian falsification:
[emphasis in original except where noted]
First, the demarcation separates the unfalsifiable issues which cannot be proven false, and therefore are either philosophical or metaphysical, from physical theories of existing material content which can be shown to be verifiable or falsifiable. This is the separation of physical science from pure opinion and nonsense.
Second, when experimental testing is performed, it is never said to validate or prove a concept; it is said to be “not falsified”. But testing is always highly contingent, especially upon technique but also upon technology limits and myriads of possible creeping errors. So further testing for falsification is necessary, leading to a possible infinite regression of tests with no conclusive answer. In other words, experimental testing is afflicted with the problem of induction, and therefor produces no immutable facts, ever, since it always might be falsified later, or un-falsified.
But here we are not concerned with the empirical problem of induction. Here the concern is whether the falsification demarcation can be useful in separating the unknowable from the potentially valid knowledge of empirical generation.
When Popper applied the demarcation to evolution, did he err? Was his assessment fundmentally incorrect?
In 1976 the following admission from Popper was documented by Mark Isaac, referencing Russell Kranz (and reproduced here in full for clarity and accuracy):
1. ”Popper's statement of nonfalsifiability was pretty mild, not as extensive as it is often taken. He applied it only to natural selection, not evolution as a whole, and he allowed that some testing of natural selection was possible, just not a significant amount.From the start there are errors in Isaac's commenting. Popper did, in fact, originally claim that the demarcation applied to the entire Darwinian hypothesis, not just to selection. And Popper did not recognize all selection as testable, as we’ll see.
Moreover, he said that natural selection is a useful theory. A "metaphysical research programme" was to him not a bad thing; it is an essential part of science, as it guides productive research by suggesting predictions. He said of Darwinism,
‘And yet, the theory is invaluable. I do not see how, without it, our knowledge could have grown as it has done since Darwin. In trying to explain experiments with bacteria which become adapted to, say, penicillin, it is quite clear that we are greatly helped by the theory of natural selection. Although it is metaphysical, it sheds much light upon very concrete and very practical researches. It allows us to study adaptation to a new environment (such as a penicillin-infested environment) in a rational way: it suggests the existence of a mechanism of adaptation, and it allows us even to study in detail the mechanism at work. And it is the only theory so far which does all that.’ (Popper 1976, 171-172)
Finally, Popper notes that theism as an explanation of adaptation "was worse than an open admission of failure, for it created the impression that an ultimate explanation had been reached" (Popper 1976, 172).
2. Popper later changed his mind and recognized that natural selection is testable. Here is an excerpt from a later writing on "Natural Selection and Its Scientific Status" (Miller 1985, 241-243; see also Popper 1978):‘When speaking here of Darwinism, I shall speak always of today's theory - that is Darwin's own theory of natural selection supported by the Mendelian theory of heredity, by the theory of the mutation and recombination of genes in a gene pool, and by the decoded genetic code. This is an immensely impressive and powerful theory. The claim that it completely explains evolution is of course a bold claim, and very far from being established. All scientific theories are conjectures, even those that have successfully passed many severe and varied tests. The Mendelian underpinning of modern Darwinism has been well tested, and so has the theory of evolution which says that all terrestrial life has evolved from a few primitive unicellular organisms, possibly even from one single organism.
However, Darwin's own most important contribution to the theory of evolution, his theory of natural selection, is difficult to test. There are some tests, even some experimental tests; and in some cases, such as the famous phenomenon known as 'industrial melanism', we can observe natural selection happening under our very eyes, as it were. Nevertheless, really severe tests of the theory of natural selection are hard to come by, much more so than tests of otherwise comparable theories in physics or chemistry.
The fact that the theory of natural selection is difficult to test has led some people, anti-Darwinists and even some great Darwinists, to claim that it is a tautology [see CA500]. A tautology like 'All tables are tables' is not, of course, testable; nor has it any explanatory power. It is therefore most surprising to hear that some of the greatest contemporary Darwinists themselves formulate the theory in such a way that it amounts to the tautology that those organisms that leave most offspring leave most offspring. C. H. Waddington says somewhere (and he defends this view in other places) that 'Natural selection . . . turns out ... to be a tautology' ..4 However, he attributes at the same place to the theory an 'enormous power. ... of explanation'. Since the explanatory power of a tautology is obviously zero, something must be wrong here.
Yet similar passages can be found in the works of such great Darwinists as Ronald Fisher, J. B. S. Haldane, and George Gaylord Simpson; and others.
I mention this problem because I too belong among the culprits. Influenced by what these authorities say, I have in the past described the theory as 'almost tautological', and I have tried to explain how the theory of natural selection could be untestable (as is a tautology) and yet of great scientific interest. My solution was that the doctrine of natural selection is a most successful metaphysical research programme. It raises detailed problems in many fields, and it tells us what we would expect of an acceptable solution of these problems.
I still believe that natural selection works in this way as a research programme. Nevertheless, I have changed my mind about the testability and the logical status of the theory of natural selection; and I am glad to have an opportunity to make a recantation. My recantation may, I hope, contribute a little to the understanding of the status of natural selection. ‘
Brush, Stephen G. 1994. Popper and evolution. Reports of the National Center for Science Education 13(4)-14(1): 29. http://www.ncseweb.org/resources/articles/8401_popper_and_evolution_9_10_2003.asp
1. Miller, David. 1985. Popper Selections.
2. Popper, Karl. 1976. Unended Quest: An Intellectual Autobiography Glasgow: Fontana/Collins.
3. Popper, Karl. 1978. Natural selection and the emergence of mind. Dialectica 32: 339-355. (excerpt at http://www.geocities.com/criticalrationalist/popperevolution.htm ) ”
What has been said here? Popper has made two claims which are contradictory; to wit:
“…has been well tested, and so has the theory of evolution which says that all terrestrial life has evolved from a few primitive unicellular organisms, possibly even from one single organism.”Second:
” However, Darwin's own most important contribution to the theory of evolution, his theory of natural selection, is difficult to test. There are some tests, even some experimental tests; and in some cases, such as the famous phenomenon known as 'industrial melanism', we can observe natural selection happening under our very eyes, as it were.The first claim is obviously false, if Popper is referring to empirical testing, which is impossible. Ancient history cannot be empirically, experimentally tested.
The second claim is most revealing: Industrial melanism refers to micro-evolution, only. The prime example is the peppered moth, which changes its coloration in a cyclic fashion and remains a peppered moth. And bacterial adaptation is also intra-genomic: micro-evolution. Popper allows that selection is testable, in micro-evolutionary scenarios.
And he still maintains that the theory is metaphysical, while also claiming it to be useful – in ways he says not how. That claim nullifies his prior unsupported statement that the theory of evolution has been “well tested”. He is being coy about his recantation, having it both ways.
From Oxford Dictionary:Has Popper been forced to fully recant his basic theory of demarcation? To recant the non-falsification of evolution? If we are interested in macro-evolution, decidedly not. And there is this final bit of evidence for that conclusion:
the prevalence of dark-colored varieties of animals (especially moths) in industrial areas where they are better camouflaged against predators than paler forms.
From Scientific American author, John Horgan:
” Early in his career, the philosopher Karl Popper (yes, cited by F and P-P) called evolution via natural selection "almost a tautology" and "not a testable scientific theory but a metaphysical research program." Attacked for these criticisms, Popper took them back. But when I interviewed him in 1992, he blurted out that he still found Darwin's theory dissatisfying. "One ought to look for alternatives!" Popper exclaimed, banging his kitchen table.”
Popper allowed himself to indulge in the inverse verificationism discussed here:
”It does appear that some people think that I denied scientific character to the historical sciences, such as palaeontology, or the history of the evolution of life on Earth. This is a mistake, and I here wish to affirm that these and other historical sciences have in my opinion scientific character; their hypotheses can in many cases be tested. [Popper, 1981, p. 611]But this approach, first assuming a law to be valid, puts the assumed law into the premise and the verification into the conclusion. That is a deductive logic violation called “Affirming the Consequent”, and also an Inductive Fallacy issue, which frequently arises as the premise is revised again and again to accommodate new inputs which affect the consequent. It also results in clashes between competing inputs which are vying for a place in the malleable hypothesis originally assumed. That tends to rip at the unity within the hypothesis itself, as it has done regarding such issues as the Cambrian explosion, classifications for anomalous creatures, and transitional species designation for feathered dinosaurs, for example. In the case of evolution, recent intellectual developments have moved away from paleontology and into meta-evolutionary concepts, which are also reflected backward, historically, and are at a higher level of unprovability, such as viral introgression; DNA “similarity” in similar portions of DNA of similar-characteristic bearing creatures (e.g. the infamous chimp/human comparison); emergence theories; and epigenetic malfunctions.
In an earlier work, Popper discussed the historical sciences in which the scientific method of theoretical sciences is used:
This view is perfectly compatible with the analysis of scientific method, and especially of causal explanation given in the preceding section. The situation is simply this: while the theoretical sciences are mainly interested in finding and testing universal laws, the historical sciences take all kinds of universal laws for granted and are mainly interested in finding and testing singular statements. [Popper, 1957, p. 143ff]What Popper calls the historical sciences do not make predictions about long past unique events (postdictions), which obviously would not be testable. (Several recent authors—including Stephen Jay Gould in Discover, July 1982—make this mistake.) These sciences make hypotheses involving past events which must predict (that is, have logical consequences) for the present state of the system in question. Here the testing procedure takes for granted the general laws and theories and is testing the specific conditions (or initial conditions, as Popper usually calls them) that held for the system.
A scientist, on the basis of much comparative anatomy and physiology, might hypothesize that, in the distant past, mammals evolved from reptiles. This would have testable consequences for the present state of the system (earth's surface with the geological strata in it and the animal and plant species living on it) in the form of reptile-mammal transition fossils that should exist, in addition to other necessary features of the DNA, developmental systems, and so forth, of the present-day reptiles and mammals.
What about repeatability? It is the observations that must be repeatable, if only to establish their validity independently of any one person's authority. This does not mean that the hypothetical mechanism or the phenomenon concerned must be repeatable or reproducible. In the experimental laboratory where the phenomena being studied are short-lived and transient, it is usually necessary to reproduce them in order to repeat the observations. But scientists must wait for the recurrence of natural phenomena—such as eclipses, earthquakes, seasonally recurring biological phenomena, and so forth. Yet, if a phenomenon is a stable, more or less permanent long-term condition, observations may be repeated anytime. A geologist may return to a geological formation to repeat or make new observations, or an anatomist or paleontologist may reexamine a museum specimen, either corroborating or refuting someone else's previous observations. Clearly, then, a hypothesis postulating a unique past event is scientific—as long as it has observable consequences for the present that can be repeatedly verified by any observer.
Thus we may conclude (as Popper did) that evolutionary theories or historical hypotheses about origins are no different than other scientific theories as far as their logical features are concerned and are just as falsifiable as hypotheses in the form of general laws and theories.”
It should be recalled that epi-cycles were explanatory, with mathematical explanations for observations. An hypothesis which has only the credentials of being explanatory, but has no hope of direct verification, replication for disciplined validation or non-falsification, is an empty hypothesis. Which is why Stephen Jay Gould called such empty hypotheses, “Just So Stories”, even while he created more of them himself (e.g. “punctuated equilibrium, which is the unprovable hypothesis created to cover the lack of data). It’s also why Popper worked out his demarcation between knowledge-generating science and metaphysical arguments, opinions and philosophical maunderings (and religious claims).
So is it true that empiricism has fallen as the necessary and sufficient conditional path to knowledge? According to this Darwinian theory of science, affirming the consequent with unprovable stories, no actual path to valid knowledge remains. Yet the first Popperian principle of falsification remains valid: if it cannot be tested and replicated independently by anyone who wishes to confirm or falsify it, then it has not the quality of universal knowledge for everyone because it is still merely inference and opinion by elites, not actual fact. And that makes it metaphysical.
Finally it should be obvious that Popper was hedging his bets with the primary assumption he makes regarding creativity as a dualist property of the universe. Popper glibly assumes as a first principle that it is the universe itself which is creative – because creativity must pre-exist the creative emergence of novelty which cannot be explained by physics, Materialism, or Determinism. Further, creativity must be attributed to some “thing”, because: Atheism.
He already denied that pure atoms could be creative, and that he was even more than a dualist, believing in three separate domains. He took no pains to justify that.
No wonder he later pounded the table when asked about his prior evolutionism, effectively recanting his earlier recantation. His demarcation was intended to keep out religious types of unfalsifiable premises, but instead, he himself allowed in a faulty pursuit which claims itself to be science, and which became dogmatically religious.
A final note from Popper:
"So it is, I hold, the possibility of overthrowing it, or its falsity, that constitutes the possibility of testing it, and therefore the scientific character of a theory; and the fact that all tests of a theory are attempted falsifications of predictions derived with its help, furnishes the clue to scientific method. This view of scientific method is corroborated by the history of science, which shows that scientific theories are often overthrown by experiments, and that the overthrow of theories is indeed the vehicle of scientific progress. The contention that science is circular cannot be upheld."NOTES:
1. Karl Popper; “Conjectures and Refutations”; 1989, Popper; 2008 Routledge Classics, p52.
2. Popper: C&R, p53.
3. Popper:C&R, p55.
4. Karl Popper; “The Logic of Scientific Discovery”; Routledge, 1935>2006; p17
5. Popper; TLSD; p17
6. Popper; TLSD; p17
7. Popper; TLSD; p266
8. Popper; TLSD; p263
9. Popper also speaks to utopianism, which possibly was a politically correct forcing issue involved in causing him to issue his “recantation”:
”In spite of all the sacrifices we have made in order to make sure that we are acting rationally, we may get exactly nowhere – although not exactly to that ‘nowhere’ which is meant by the word ‘Utopia’.
Again, the only way to avoid such changes of our aims seems to be to use violence, which includes propaganda, the suppression of criticism, and the annihilation of all opposition. […] The Utopian engineers must in this way become omniscient as well as omnipotent. They become gods. Thou shalt have no other gods before them. ”
Popper; C&R; p484
10. Karl Popper; "The Open Society and It's Enemies"; Routledge; 1945; p288.
11. Popper; TOSAI; p362.