The Poverty of Popperism
"There is nothing so absurd but some philosopher has said it." (Cicero, De Divinatione.)
If it were not so serious, it would be comical. In the most pompous manner, the advocates of the most unscientific theory imaginable immediately elbowed aside all other trends and loudly proclaimed themselves to be the philosophy of science. It was the intellectual equivalent of gate-crashing a party. And, as sometimes happens, the people at the party may be too polite, or too afraid of a bunch of rowdies, to shut the door, so they just keep quiet and let them in. Of course, it always helps if someone on the inside calls out: "Oh, its O. K., theyre friends of mine!"
In the development of quantum mechanics, an important role was played by Niels Bohr and Werner Heisenberg. They worked together, and developed the so-called Copenhagen Interpretation of quantum mechanics, which we have already commented on. There was, however, a difference in their approach. Whereas Bohr was basically a pragmatic scientist, Heisenberg was always inclined to a more philosophical approach, and, for a time, accepted the theories of logical positivism. The whole Copenhagen Interpretation of quantum mechanics is permeated with the spirit of subjective idealism as a result.
It was bad enough that this trend should claim to speak for "modern science" in the field of philosophy. But that was not enough for them. They had to teach the scientists their business as well. If they were really the philosophy of science, then all scientists must heed them! They had worked out a "scientific method" which was foolproof. Now everyone must accept it, on pain of being denounced as unscientific. And in case anyone thought they were joking, just look at the job they did on psycho-analysis!
There was only one slight problem in all this. The standards of so-called logicality set by these ladies and gentlemen have nothing whatever to do with the actual practice of science itself. Most practical scientists just shrug their shoulders, and get on with their work as if these people were not there, just like those who move into the kitchen to get away from those noisy party-crashers; which does not prevent them from continuing to make an awful lot of noise.
One of the noisiest was Sir Karl Popper, who died recently. Like Napoleon, who literally crowned himself Emperor, Popper proclaimed himself the philosopher of science, and, without waiting for the outcome of a referendum on the subject, proceeded to hold court on a world scale. In between ferocious polemics against Marx (whom he did not understand), he wrote a great deal on the method of science (which he interpreted in a completely one-sided way). It is a measure of the vacuum in modern philosophy that this kind of nonsense was taken seriously for so long.
Induction Versus Deduction?
In 1934, Popper, then living in Vienna, published his book The Logic of Scientific Discovery. In this work, Popper completely rejects the method of induction, insisting that all conclusions must be drawn from logical deduction. Popper specifically rules out the method of induction, based on observation. To qualify for Poppers certificate of "science-worthiness," a theory must be internally consistent, must not be a tautology, and must make predictions that can be tested. Moreover, he maintained that the results of a test cannot verify a theory, only falsify it.
All of this sounds very nice, and is in complete accord with the method of formal logic. But it has got very little to do with the actual practice of science. One physicist commented wryly that Poppers ideas were strategically sound but tactically indefensible, in other words, fine in (formal logical) theory, but, like an umbrella full of holesuseless precisely for the purpose for which it was intended.
Induction (from the Latin inducere, to lead in) is another method of reasoning. It was already known to Aristotle, but achieved wide acceptance during the Renaissance, when it was championed by Bacon and Galileo. As a form of reasoning, induction proceeds from single facts to general propositions. Men and women have always made such generalisations on the basis of their experience, often reaching correct conclusions, sometimes not.
Let us consider an example of inductive reasoning. A child burns its hand on a flame, and draws the conclusion, on the basis of experience that it is not a good idea to get too close to fire. "Fire (in general) burns." That is an inductive reasoningfrom the particular to the general. In this case, the conclusion is perfectly valid and rather useful. But consider another example. A turkey is visited every morning by a nice old lady with a bag of corn in her hand. The turkey, by the method of inductive reasoning, might very well conclude that the kind lady means food. This conclusion is drawn from the same experience repeated many times364 times, to be exact. Then, one morning, the farmers wife appears with a butchers knife in her hand. Here the turkeys inductive logic proves to be somewhat defective, and does not really help it to clarify its existential dilemma!
Scientific induction, like its popular equivalent, also consists of drawing conclusions from a whole class based on the number of elements of that class. But here the grounds for conclusion are provided by the discovery of essential connections between the elements studied, which show that the given feature must be possessed by the whole class. The task of discovering these necessary connections involves detailed observation. Thus, induction signifies experimental study of things, in such a way that we pass from single facts to generalisations.
The method of deduction is, on the face of it, the exact opposite of induction. Deduction consists of proving or inferring a conclusion from one or more premises by the laws of logic. The deductive method does not set out from particular experiences, but from so-called axioms, which are assumed to be correct from the start. This is the traditional method of mathematics, for example classical geometry, based on the axioms of Euclid, which were for centuries supposed to represent absolute truths, valid for all time, under all circumstances. Deductive reasoning therefore proceeds from the general (law) to the particular.
The struggle between induction and deduction goes back to the 17th century, to the different approaches adopted by two great scientific thinkersBacon and Descartes. The Englishman Bacon was the father of empiricism, and the method of inductive reasoning, which attempts to derive theories from observed facts alone. In Bacons case, the obsession with observation proved fatal; he died of bronchitis as a result of an early experiment in refrigeration, involving stuffing a chicken with snow.
Descartes approached science from a diametrically opposite standpoint. Taking Euclids geometry as his model, he attempted to develop consistent and coherent theorems derived from pure reason, without recourse to the unreliable evidence of the senses. His method was that of rationalism, which became the main tradition in France. Bacons empiricism triumphed on the other side of the Channel. Both men, in different ways, advanced the cause of science, and both made important discoveries.
However, neither deduction nor induction on their own are capable of grasping the whole picture. The problem with Bacons method is that the facts do not select themselves. You need an initial theory (a hypothesis) even to decide what observations to make in the first place. Moreover, the results of induction always have a more or less provisional character. For example, a person who had observed a hundred swans might draw the conclusion that all swans were white. This is an inductive conclusion. But it would be wrong, because some swans are black. Engels makes the point that "The empiricism of observation alone can never adequately prove necessity." (The Dialectics of Nature, p. 304.)
We therefore did not have to wait for Sir Karl to point out the limitations of inductive logic. However, to deny induction altogether is to jump from the frying pan into the fire. Induction plays a necessary role in science, as well as in everyday life. Is it really necessary for somebody to drink all the water in the sea before being prepared to admit that sea water is salty? Poppers attempt to eliminate induction from science shows a lamentable ignorance both of the true relationship between deduction and induction, and of how science works in real life.
Until the end of the 19th century, the deductive method was used almost exclusively in mathematics. Not until the 20th century were attempts made to apply it to fields such as physics, biology, linguistics, sociology, etc. Despite all the impressive claims made on its behalf, experience shows that the axiomatic-deductive method is quite limited in what it can achieve. The controversy between induction and deduction is pointless, since, in practice, induction always exists together with deduction. Neither is self-sufficient as a method, but, in dialectical materialism, they are combined as different aspects of the process of cognizing reality, which are inseparably connected, and determine each other.
The Economist article already mentioned goes on to criticise Poppers rejection of the inductive method:
"A number of philosophers also question Poppers rejection of induction. The use of induction, they say, is logically unsatisfactory but inescapable. Deductions about the real world are only as good as the assumptions about the real world on which they are based. These assumptions rest on induction, as does the scientists interpretation of the experimental results that test the conclusions drawn from them. Both in forming a hypothesis and in interpreting tests of it, a scientist makes the basic assumption that nature will behave in other places and at other times as it behaves here and now. That is an inductive assumption." And it continues:
"Dr. Jennifer Trusted is one British philosopher who puts induction in perspective. Induction, she says, is essential but not sufficient for knowledge of the real world. The same could be said for deduction."
This last observation is absolutely correct, and goes to the heart of the matter. Neither induction nor deduction, taken on its own, is sufficient. It is necessary to combine them, which is just what dialectics does. Deduction is also a conclusion, and therefore induction is also a kind of deduction. On the other hand, all deductions are, in the last analysis, derived from material reality. This is true even of axioms, which are supposed to be the products of "pure theory." For example, Euclids axiom that a straight line is the shortest distance between two points is clearly the result of long experience and observation. Engels explains the one-sidedness of both induction and deduction, when taken in isolation, and also explains the dialectical relation between them:
"Induction and deduction belong together as necessarily as synthesis and analysis. Instead of one-sidedly lauding one to the skies at the expense of the other, we should seek to apply each of them in its place, and that can only be done by bearing in mind that they belong together, that they supplement each other." (The Dialectics of Nature, p. 302.)
What Can we Predict?
Poppers insistence that all conclusions must be drawn by deduction, then, is at variance with the reality of scientific practice. Indeed, those areas of sciencelike certain branches of particle physics and cosmologywhich have developed an excessive dependence on the method of deduction and abstract reasoning, are getting into a deeper and deeper mess. Nor is the business of the testing of a new hypothesis as straightforward as Popper makes out. There are many theories which are in daily use, despite the fact that they are known to be quite inadequate, for the simple reason that they are the best available; an example is Hookes law, used by engineers to check the relationship between stresses and strains in a material.
In a very perceptive article (unfortunately unsigned) published in the Science section of The Economist in December 1981, Poppers views on science are exposed to a searching analysis, with quite devastating results:
"There are a lot of experiments where you cannot restrict the results to yes-or-no answers or where it is extremely hard to interpret what the answers are, because of the so-called signal-to-noise ratio. Suppose you repeat an experiment six times and get the result you predicted only twice. Does that prove the prediction was wrong? Or that four times out of six you failed to get the experiment right? In biology, such results are common: the vagaries of nature are notorious.
"While scientists strive for unambiguous answers, often they have to settle for less. And even if you do get results that unambiguously show the prediction of a theory is wrong, it is still not always clear what you have falsified. Strictly speaking, testing an isolated hypothesis is impossible. Consciously or unconsciously, the scientist assumes much else from the pyramid of knowledge besides the hypothesis tested." (The Economist, December 26th 1981, p. 101.)
The emphasis on prediction as a necessary precondition of the scientific method has been greatly exaggerated, and does not conform in the slightest to the reality of science. An astronomer can sometimes predict the position of a star many millions of years hence. But Darwin could not predict what species would evolve in a million years time. Geologists cannot predict precisely the time and place of an earthquake. And with meteorologists, the situation is still more hopeless. Even with all the armoury of modern computers and satellite technology behind them, they can only predict the weather with any degree of accuracy for a maximum of three days. Incidentally, even astronomy is not such an exact science as used to be thought. There are plenty of unpredictable phenomena in cosmology, yet no-one in their right mind would deny that astronomy is a science because it is unable to predict precisely where the next star will be born.
The reality of science certainly does involve making predictions to test out theories, although the nature of the prediction and the type of experimental "test" will vary enormously from laboratory test tubes to vast astronomical distances. Just because some predictions are not, and cannot be made, does not rule out the idea as a scientific method. There are sciences and sciences, and there are predictions and predictions. Predictions involving simple linear systems can be made with a high degree of certainty. But complex systems are difficult, or impossible to predict with any degree of accuracy.
For all the satellites and computers, it is impossible to predict the weather accurately more than three days in advance. Is meteorology a science, or not? Earthquakes cannot be predicted, and there are no neat laboratory experiments to prove the theories of geology. Is the latter a science, or is it not? And what about the predictions of a doctor? Even the best doctors make mistaken diagnoses, sometimes with fatal results. Is medicine a science? Clearly, it is, but not a precise science like some branches of physics.
When we reach a field like psychology, things get even more complicated. Psychology, as a science, is still in its infancy. One cannot yet speak of a fully worked-out body of ideas which is generally accepted in this most complex field, involving the basic driving-forces of human behaviour. And when we come to sociology, which, after all, deals with the complex behaviour of masses, the huge amount of variables makes the task of prediction doubly difficult. Difficult, yes. Impossible, no. For in human society also there are certain patterns of behaviour, certain processes, which can be identified and explained. General conclusions can be drawn, and, yes, predictions made, which can be tested in practice. Only dont expect the same precise degree of accuracy in such predictions as you would hope to find in a carefully-conducted laboratory experiment!
At best, it is possible to predict the most general tendencies in society, and even these predictions must be constantly revised, added to and modified in the light of experience. In the end, they may be falsified by events, for a number of reasons, just as a even the best doctors diagnosis may turn out to be wrong. Does the doctor then draw the conclusion that diagnosis in general is an unscientific occupation, a waste of time? Or does he go back and try to discover the source of his error, in order to learn from it? The real question that should be asked is: Do we believe that it is possible to obtain a rational understanding of the laws that govern social evolution? If the answer is no, then all further discussion is pointless. If human history is seen as an essentially meaningless string of accidents, then there is no point in trying to understand it. But if science has succeeded in discovering the laws which governed the development of humankind in the remote past, based on the extremely scanty evidence of a few precious fossils, then it is not at all obvious why it should be impossible to uncover the laws which determined the evolution of our species for the last 10,000 years. Yet this is declared out of bounds by Professor Popper. All who attempt to do this will be immediately be condemned for the heinous crime of historicism.
Thus, we are entitled to ask about the far-flung galaxies, and the smallest particles of matter, but if we attempt to arrive at a rational understanding of society, of historythat is to say of ourselves, who we are and where we came fromthat is not allowed. The arbitrary nature of this prohibition is so glaring that one cannot avoid asking what the reason for it is. Is it really to do with science? Or might it have more to do with certain vested interests which do not want people to ask too many questions about the past and present of the type of society in which we live, for fear that they might draw all the wrong conclusions about the type of society we would like to live in in the future.
Nothing to Do with Science
Poppers attempt to elevate the rules of deduction and formal logic above all else is the 20th century equivalent to the dictatorship of the Churchs one-sided and rigid caricature of Aristotle in the Middle Ages. Once again we have the attempt to force science into the straitjacket of a rigid and preconceived idealist schema, which lays claim to the status of an absolute truth to which everyone must bend the knee. Unfortunately, unruly, rebellious, contradictory nature will not submit meekly to such treatment. However self-consistent logic may be, it provides no ready-made answers about the world. Indeed, as we have seen, logic and mathematics in the 20th century has found it impossible to deal with contradictions even in its own house, as in the following sentences: "The next sentence is false. The previous sentence is true." Professional logicians cannot even agree among themselves whether this, and other "anomalies" have been resolved. Yet this did not prevent the likes of Sir Karl Popper from laying down the law for the whole domain of human thought.
The problem is that science, lives in the physical world, that crude world of contradictory, non-linear material reality. It is simply not good enough for the philosophy of science. Karl Popper is not a bit bothered about the discrepancy. If science does not match up to the stern criteria of the verification principle, so much the worse for science! Let us hear what the great man himself has to say on the subject:
"Science is not a system of certain, or well-established, statements; nor is it a system which steadily advances towards a state of finality. Our science is not knowledge (episteme): it can never claim to have attained truth, or even a substitute for it, such as probability.
"Yet science has more than mere biological survival value. It is not only a useful instrument. Although it can attain neither truth nor probability, the striving for knowledge and the search for truth are still the strongest motives of scientific discovery.
"We do not know: we can only guess. And our guesses are guided by the unscientific, the metaphysical (though biologically explicable) faith in laws, in regularities which we can uncoverdiscover. Like Bacon, we might describe our own contemporary sciencethe method of reasoning which men now ordinarily apply to natureas consisting of anticipations, rash and premature, and of prejudices." (Quoted in Ferris, pp. 797-8, our emphasis.)
These few observations, delivered in a typically modest style quite in the tradition of Herr Dühring, were made in a lecture delivered to the Aristotelian society in Oxford in 1936. The lecturer later recalled with some irritation that "the audience took this for a joke, or a paradox, and they laughed and clapped." Evidently, they did not know their Karl Popper! There was no joke intended. He meant every word. For Popper and his disciples, the purpose of science is not to discover truths about the world, but merely a formal logical exercise, like chess or a crossword puzzle.
What is one to say about all this? At the end of the 20th century, when the discoveries of science have attained unheard-of peaks, we are informed that science cannot really know anything at all. On this issue, we completely concur with the following assessment:
"A distinction should be made between theories and facts. Scientists assume theories; they know facts to be true, within acceptable limits of confidence. As time advances, they replace one theory with another, arguably a better one. What should be beyond argument is that there is an accretion of known facts.
"On the whole, science is true. To deny that man knows more about the workings of nature now than he did in the Middle Ages is perverse. Undoubtedly, some scientific discoveries are false and scientists are often a bit irrational in how they set about finding things out. But the alternative to accepting that there is a strong measure of truth in science is to go back to blaming a witch when the cow is sick." (The Economist, ibid., p. 103.)
The final refutation of Popperism and logical positivism in general is that, for all its bragging claims, it has nothing to do with the realities of science. This is shown by the attitudes of scientists, including, as we have seen, of those who could be expected to be sympathetic to it. This is what Niels Bohr had to say, after a conference of scientists and logical positivists held in Copenhagen about the philosophical implications of quantum mechanics:
"For my part, I can readily agree with the positivists about the things they want, but not about the things they reject. All the positivists are trying to do is to provide the procedures of modern science with a philosophical basis, or, if you like, a justification. They point out that the notions of the earlier philosophies lack the precision of scientific concepts, and they think that many of the questions posed and discussed by conventional philosophers have no meaning at all, that they are pseudo problems and, as such, best ignored. Positivist insistence on conceptual clarity is, of course, something I fully endorse, but their prohibition of any discussion of the wider issues, simply because we lack clear-cut enough concepts in this realm, does not seem very useful to methis same ban would prevent our understanding of quantum theory." (Quoted in T. Ferris, op. cit., p. 822, our emphasis.)
The famous physicist Wolfgang Pauli observed that the logical positivists merely used the term metaphysics as a kind of swearword, or at best, as an euphemism for unscientific thought. "I should consider it utterly absurdand Niels (Bohr), for one, would agreewere I to close my mind to the problems and ideas of earlier philosophers simply because they cannot be expressed in a more precise language. True, I often have great difficulty in grasping what these ideas are meant to convey, but when that happens, I always try to translate them into modern terminology and to discover whether they throw up fresh answers." (Quoted in T. Ferris, p. 824.)
Finally, let us call as a key witness for the prosecution a man who might be expected to support the logical positivist line enthusiasticallyWerner Heisenberg. In fact, he generally followed this line in the beginning, denying the independence of physical reality from the act of observation, insisting on the "indeterminateness" of processes at the sub-atomic level, and so on. However, as a scientist, involved in serious research, Heisenberg had to come to terms with the objective reality of the physical world. In the end, the absurd claims of the self-appointed philosophers of science were too much even for him.
"The positivists," he wrote, "have a simple solution: the world must be divided into that which we can say clearly and the rest, which we had better pass over in silence. But can anyone conceive of a more pointless philosophy, seeing that what we can say clearly amounts to next to nothing? If we omitted all that is unclear, we would probably be left completely uninteresting and trivial tautologies." (Ibid., p. 826.)
After decades of wandering in this arid desert, the most forward-looking scientists have finally turned their backs on a philosophy which taught them absolutely nothing either about the way nature works or how to understand it. The advent of the theories of chaos and complexity marks a decisive break with the narrow limitedness of the philosophy of science, and an approximation to a dialectical view of nature. The attitude of the new generation of scientists to the existing schools of thought is summed up in the following observations by the biologist Stuart Kaufmann on why he decided not to study philosophy:
"It wasnt that I didnt love philosophy. Its that I distrusted a certain facileness in it. Contemporary philosophers, or at least those of the 1950s and 1960s, took themselves to be examining concepts and the implications of conceptsnot the facts of the world. So you could find out if your arguments were cogent, felicitous, coherent, and so on. But you couldnt find out if you were right." (M. Waldrop, Complexity, p. 105.)
There is an English proverb: "Little things please little minds." Those who place impossible demands upon science and then, when their demands are not met, draw the conclusion that science is not really "true" say nothing at all about science, but quite a lot about a trivial method which seeks simple answers to complex questions and complains when they are not forthcoming. The old claims to represent the philosophy of science are as dead as a doornail. To paraphrase what Marx once said about Matthew Arnold, the philosophy of science is too good for this world.
