In thinking of late about science, and how it isn't a prediction machine correlating expermintal measurements, I keep thinking of the notion of paradigms. It isn't perfectly clear how this is different on the one hand from really basic notions typical of the scientific enterprise, both narrowly and broadly construed. For example, the notions of causality; truth is correspondence to reality; nature is lawful (or if you insist on speaking unnaturally, nature displays some regularities to which we do not find exceptions and which heuristically used can make repeated valid predictions to the outcome of experiments); nature is consistent or coherent or intelligible (yes, we all know about quantum woo, but the paradox is that despite a theory that is set in a Hilbert space nonetheless we get results always compatible with good old Einsteinian spacetime.) Although not even these notions are held to be above revision, in practice they have been incorrigible because they are more inductions than deductions from theories that have had to be revised. If these notions are part of the scientific paradigm, which seems a valid construal of the notion of paradigm, then the scientific paradigm has never successfully been replaced. Merely (a giant word!) modified. In this sense, the notion of a succession of paradigms succeeding each other willy nilly is utterly refuted.
On the other hand, if paradigms refer to specific ideas, things like atoms; the distinction between energy and momentum; the field concept; the wave concept; the ether; phlogiston; the Ptolemaic model; spontaneous generation; Newtonian absolute time, then one thing that pops out from even this cursory list is that such paradigms are often not wholly overthrown. Consider atomic and wave and field conceptions of phenomena, all still live and kicking in one context or another. The coexistence of such broad differences in how scientists view things seems incompatible with the notion of incompatible paradigms that can only replace each other. But these notions are so general it is hard to see that you could just demote them to simple concepts.
Another thing that emerges is that the dubious element in these constructs, such as the centrality of the Earth or the doubtful coherence of a notion of absolute time apart from change, were usually challenged by alternatives. Consider Aristarchus' model or the objections to Newton's absolute time (and his theory of light, as well.) A one paradigm may be as extinct as the dinosaurs, replaced by a ratty little one that had, after the eon scurrying in the undergrowth, suddenly grows, multiplies and branches out. But it didn't come from nowhere.
And it has often been observed that the empirical observations of these theories, and the predictions they led to, though not the verbal forms and pictorial analogies, were conserved. The "paradigms" if that is what you wish to call such related sets of concepts that articulate fundamental theories (scientific explanations) of the world are connected to each other. They are not arbitrary. Of the few that are wholly obliterated by induction, a bare few have seemed to reemerge, notably spontaneous generation, and in a few advanced speculative models, the ether and absolute time. Perhaps there was an inspirational aspect (but for humans, inspiration can come from religion, philosophy, play, dreams, whatever serves to propel the speculative moment of science---but it isn't science if you don't try to find out if it's true.) Closer investigation reveals that chemical biogenesis is nothing like spontaneous generation. Etc.
Lastly, if a change in paradigm can be usefully labeled a scientific revolution, then the notion of counterrevolution really should be allowed. In biology, resistance to evolutionary science has plainly been fostered by a religious paradigm trying to turn back the clock. I think it is pretty obvious how reactionary weltanschaungen contribute to economic or psychology or history. Thus it appears that the paradigm of science as a random sequence of paradigms unconnected to each other is wrong. And that appearances of retrogression can be reasonably attributed to rather literal reaction.
In short, the dwellers in paradigms may be happy, but they are not useful.
Tuesday, July 24, 2012
Monday, July 23, 2012
Science Broadly Defined
Many, maybe most, writers on science define science pretty much as something Europeans have done since Galileo. Some of them mention Francis Bacon occasionally. The focus is on scientific method, defined in practice as controlled experiments. In this view, there not only weren't professional scientists but there were no amateur scientists before the Italian. They are generally particularly careful to explain that the ancient Greeks didn't do science.
But is this true? Aristotle did dissections. Those are not controlled experiments and don't fit the European science model. Measuring instruments were also pioneered by the ancient Greeks, as the Tower of the Winds shows us. Nor is that a controlled experiment. Aristotle earned eternal contempt from philosophers for his insistence on making lists and categories and principles, dutifully cataloging facts, a noxiously low-minded, dull and painfully exact practice. Nor is this a controlled experiment. Some people avoid the issue by using the phrase formal science. This would be okay if it didn't avoid the issue of whether people like Aristotle et al. were doing science, formal or not. This matters because it confuses the issue of what "scientia," that is, knowledge really is.
May I suggest that science is any systematic way of organizing and acquiring new knowledge, information that is verified as corresponding to reality? As every devotee of the sweet science knows, any field can have its lore organized and verified in practice. Systematic observation, making allowances as best as possible for error and bias, including different perspectives and critical analysis of conflicting testimony, recorded for comparison and analysis; collections of specimens; mapmaking; taxonomy; generalization and such have led to major advances, for instance the discovery of the fossil record and its associated law and other principles. This kind of thing is looked down upon as lowly induction. My reading of the history of science however has been that the greatest problem in the end has been statements and beliefs falsely attributed the status of fact. The explanations can be modified or replaced, but for sheer total confusion a false impression is pretty much impossible to beat.
Closely related, obviously, is the advance of instrumentation for measurement. Creating the microscope is not a controlled experiment. Nor for that matter is examining everything you can under it. Nonetheless the advent of new instruments (and maps and other graphical aids involved in presenting the information) has been the driver of far more scientific discovery than the desire of faslfiying an hypothesis. J.D. Bernal, whose work is pretty much abandoned, documents the process much better than I could. I believe it is ignored because it is unwelcome not because it is refuted.
Phrasing this another way, induction is far, far more powerful a tool for scientific investigation than is popularly conceded. Cartography and taxonomy are not experimental sciences in the formally philosophical way, but in their engagement with experience are crucially empirical. They emphasize getting all the evidence, presenting the evidence as clearly as possible and getting the facts right. Most people do not do this. By contrast they are pragmatic; seeking only the information to hand; oftentimes consulting any authority; quitting when they get confirmation; making no argumentation at all, merely presenting conclusions as if by fiat; rarely analytical or critical. In the daily routines of life this is natural enough. Also, since science is now professionalized, many people merely consult scientific authorities.
Nonetheless, these practices are I believe a huge component of scientific investigation, and the lowly simple facts and (obvious?) inductions comprise a huge portion of the corpus of scientific knowledge. Of these inductive generalizations, some of vitally important ones include such notions as naturalism, causality and the consistency/regularity/lawfulness of nature. These hugely important concepts are justified a posteriori, not a priori. And they are the real demarcators of science, both narrowly and broadly defined.
The importance of defining science broadly is two fold. First, it highlights the importance of inductive knowledge. Darwin did not provide experimental evidence for natural selection. Wegener did not provide any mechanism at all for continental drift. "Strata" Smith did not do experiments to
show how fossil order could have arisen. Nonetheless, despite not doing formal controlled experiments these men did good science. The failure to find any evidence of anything that acted remotely like the crystal of the celestial spheres, or signs of forces that could move said spheres, could have been (and should have been) read as a sign that the Ptolemaic model was incorrect, that the hypothesis of the spheres was an unjustified ad hoc element. Newton's incorrect notion of an absolute time was not sufficient reason to reject the empirical success of his laws of gravitation and motion. The radical changes that sometimes occur in the formulation of explanations is never accompanied by similarly radical changes in the corpus of knowledge. New ideas may be necessary, but old ideas never come back, because they've been refuted. The corrigibility of science will never, never permit the return of astrology or other religious ideas, no matter what. In that sense, the corrigibility of science is wholly irrelevant to a simple (but to some bitter) truth: Science is knowledge.
Second, the numerous tools in science broadly defined are obviously found in many social studies. It is not universally the case. Many historians for example have difficulties with the idea of causality! Others insist on attributing strange powers to nonmaterial abstractions, such as ideas or the Zeitgeist. But it is equally obvious that many social scientists are in fact scientists, even if the subject matter does not permit much in the way of formal controlled experimentation. The resistance to allowing that there may be such a thing as social science, and the insistence on narrowly redefining science to exclude it, seems almost universally to be motivated by a desire to remove any social belief from claiming the status of knowledge. Considering that social beliefs include such notions as racism, it is hard to have much respect for this stance as protecting the gullible public from scientistic blindness to the richness of social life and the complexity of moral/political questions!
But is this true? Aristotle did dissections. Those are not controlled experiments and don't fit the European science model. Measuring instruments were also pioneered by the ancient Greeks, as the Tower of the Winds shows us. Nor is that a controlled experiment. Aristotle earned eternal contempt from philosophers for his insistence on making lists and categories and principles, dutifully cataloging facts, a noxiously low-minded, dull and painfully exact practice. Nor is this a controlled experiment. Some people avoid the issue by using the phrase formal science. This would be okay if it didn't avoid the issue of whether people like Aristotle et al. were doing science, formal or not. This matters because it confuses the issue of what "scientia," that is, knowledge really is.
May I suggest that science is any systematic way of organizing and acquiring new knowledge, information that is verified as corresponding to reality? As every devotee of the sweet science knows, any field can have its lore organized and verified in practice. Systematic observation, making allowances as best as possible for error and bias, including different perspectives and critical analysis of conflicting testimony, recorded for comparison and analysis; collections of specimens; mapmaking; taxonomy; generalization and such have led to major advances, for instance the discovery of the fossil record and its associated law and other principles. This kind of thing is looked down upon as lowly induction. My reading of the history of science however has been that the greatest problem in the end has been statements and beliefs falsely attributed the status of fact. The explanations can be modified or replaced, but for sheer total confusion a false impression is pretty much impossible to beat.
Closely related, obviously, is the advance of instrumentation for measurement. Creating the microscope is not a controlled experiment. Nor for that matter is examining everything you can under it. Nonetheless the advent of new instruments (and maps and other graphical aids involved in presenting the information) has been the driver of far more scientific discovery than the desire of faslfiying an hypothesis. J.D. Bernal, whose work is pretty much abandoned, documents the process much better than I could. I believe it is ignored because it is unwelcome not because it is refuted.
Phrasing this another way, induction is far, far more powerful a tool for scientific investigation than is popularly conceded. Cartography and taxonomy are not experimental sciences in the formally philosophical way, but in their engagement with experience are crucially empirical. They emphasize getting all the evidence, presenting the evidence as clearly as possible and getting the facts right. Most people do not do this. By contrast they are pragmatic; seeking only the information to hand; oftentimes consulting any authority; quitting when they get confirmation; making no argumentation at all, merely presenting conclusions as if by fiat; rarely analytical or critical. In the daily routines of life this is natural enough. Also, since science is now professionalized, many people merely consult scientific authorities.
Nonetheless, these practices are I believe a huge component of scientific investigation, and the lowly simple facts and (obvious?) inductions comprise a huge portion of the corpus of scientific knowledge. Of these inductive generalizations, some of vitally important ones include such notions as naturalism, causality and the consistency/regularity/lawfulness of nature. These hugely important concepts are justified a posteriori, not a priori. And they are the real demarcators of science, both narrowly and broadly defined.
The importance of defining science broadly is two fold. First, it highlights the importance of inductive knowledge. Darwin did not provide experimental evidence for natural selection. Wegener did not provide any mechanism at all for continental drift. "Strata" Smith did not do experiments to
show how fossil order could have arisen. Nonetheless, despite not doing formal controlled experiments these men did good science. The failure to find any evidence of anything that acted remotely like the crystal of the celestial spheres, or signs of forces that could move said spheres, could have been (and should have been) read as a sign that the Ptolemaic model was incorrect, that the hypothesis of the spheres was an unjustified ad hoc element. Newton's incorrect notion of an absolute time was not sufficient reason to reject the empirical success of his laws of gravitation and motion. The radical changes that sometimes occur in the formulation of explanations is never accompanied by similarly radical changes in the corpus of knowledge. New ideas may be necessary, but old ideas never come back, because they've been refuted. The corrigibility of science will never, never permit the return of astrology or other religious ideas, no matter what. In that sense, the corrigibility of science is wholly irrelevant to a simple (but to some bitter) truth: Science is knowledge.
Second, the numerous tools in science broadly defined are obviously found in many social studies. It is not universally the case. Many historians for example have difficulties with the idea of causality! Others insist on attributing strange powers to nonmaterial abstractions, such as ideas or the Zeitgeist. But it is equally obvious that many social scientists are in fact scientists, even if the subject matter does not permit much in the way of formal controlled experimentation. The resistance to allowing that there may be such a thing as social science, and the insistence on narrowly redefining science to exclude it, seems almost universally to be motivated by a desire to remove any social belief from claiming the status of knowledge. Considering that social beliefs include such notions as racism, it is hard to have much respect for this stance as protecting the gullible public from scientistic blindness to the richness of social life and the complexity of moral/political questions!
Sunday, July 22, 2012
Popper's Demarcation
This was not a full consideration, but was a commentary on Popper's reformulation of his German work later in Conjectures and Refutations, linked to as part of a discussion in Why Evolution Is True. My original comments (numbering added) were:
1."It is easy to obtain confirmations, or verifications, for nearly every theory — if we look for confirmations."
This is very close to setting up a straw man, which is not a very good way to begin.
Every statistically controlled experiment or study sets up a bar for confirmation which in my opinion is not making it easy to find confirmation. We are apparently meant to assume the crudest and simplest (most naive) kind of activities, it appears.
2."Confirmations should count only if they are the result of risky predictions; that is to say, if, unenlightened by the theory in question, we should have expected an event which was incompatible with the theory — an event which would have refuted the theory."
Unenlightened by the germ theory, we should expect people to die, perhaps from cancer, without any signs of microbes. A risky prediction that the germ theory makes is that fatal diseases will be accompanied by germs, a risky prediction promptly disconfirmed by the autopsy of a victim of lung cancer. Ergo the germ theory is scientific, but wrong. This erroneous conclusion demanded by this principle of Popper’s suggests that no theory can be stretched beyond what it’s evidential foundation and internal logic permit, whether that allows "risky" conjectures or not. The failure of risky prediction may merely mean that the theory’s limits of validity have been reached.
3."Every "good" scientific theory is a prohibition: it forbids certain things to happen. The more a theory forbids, the better it is."
It is not clear how this is very different frm saying that the more a theory predicts, the better it is. The cell theory forbids that living things be composed of anything but cells or cell products. This formulation makes the cell theory sound like it is refuted by the abiogenetic origin of life.
Worse, this formulation forgets the most basic prohibition in science, the repudiation of the supernatural. Far better to say that every good scientific theory accepts the metaphysical postulates of philosophical materialism.
4."A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice."
This is just wrong. String theory or the multiverse concept may be wrong, and are as of this time immune to testing and refutation, but they are scientific in that they are deductions from well-tested scientific theories. Comparing the spectra of the Moon and green cheese to test the theory they are the same makes for a testable theory. The theory that there is however a Moon in a green cheese in another galaxy however is impossible to refute. According to this criterion, the first is a scientific
theory, but the latter is not.
5."Every genuine test of a theory is an attempt to falsify it, or to refute it. Testability is falsifiability; but there are degrees of testability: some theories are more testable, more exposed to refutation, than others; they take, as it were, greater risks."
The testability of theories lies partly in the phenomena they attempt to explain. This is not relevant to the scientificity of the theory. This criterion seems to be what I think they call a category mistake.
6."Confirming evidence should not count except when it is the result of a genuine test of the theory; and this means that it can be presented as a serious but unsuccessful attempt to falsify the theory. (I now speak in such cases of "corroborating evidence.")"
Again, disease germs are not found in all dead bodies. I suppose Virchow’s postulates could be rewritten as negative, disproof steps, but it is hard to see how this is useful. Worse, in complex phenomena, false negatives due to overextension of the theory will be far more likely. The real need for theories to be compatible with each other is entirely overlooked. (Incidentally, this is not really different from the insistence on the insistence on "risky" hypotheses.)
7."Some genuinely testable theories, when found to be false, are still upheld by their admirers — for example by introducing ad hoc some auxiliary assumption, or by reinterpreting the theory ad hoc in such a way that it escapes refutation. Such a procedure is always possible, but it rescues the theory from refutation only at the price of destroying, or at least lowering, its scientific status. (I later described such a rescuing operation as a "conventionalist twist" or a "conventionalist stratagem.")"
Only the simplest phenomena do not require numerous auxiliary hypotheses in theories. Further, life is ad hoc and it is not at all clear what possible criteria Popper has for labeling an auxiliary hypothesis ad hoc. Is the breaking of a natural damn an ad hoc hypothesis for the Channeled Scablands, which would otherwise refute theories of stratigraphy? A legitimate philosophy of science would be asking those questions, I thnk, not foolishly denying the necessity of auxiliary hypothese in perfectly good science.
8."We can sum up all this by saying that the criterion of the scientific status of a theory is its falsifiability, or refutability, or testability."
There are many trivial experiments. There are many false negatives from significant experiments. Experimental results must be interpreted in light of theories of many kinds of phenomena, and the experimental evidence for them, which means that scientificity also lies in the unitarity of explanations of nature. A parapsychologist can hypothesis ESP, make a risky prediction, test it, fail to refute it, yet we can confidently assert that sending information faster than light is impossible and that parapsychology therefore is not a scienctific enterprise. No matter how much it fits Popper’s criteria.
I understand that Popper once denied the theory of natural selection scientific status, which seems to me a natural conclusion of these criteria. Any experiments that falsify natural selection a la Popper really do tend to be rather trivial, don’t they?
Second thoughts (you knew this was coming didn't you?):
1. By the same token, it is easy to obtain falsifications for any theory, if we want to look for them. Sometimes it seems that those who adhere to a falsificationist perspective do so because it makes it easy to rule out tout court whole sciences without troubling to actually refute them. Popper personally, as The Open Society and Its Enemies shows, was primarily concerned to deny any social study the dignity of science. Creationists in my observation have very commonly adhered to a falsficationist perspective because, as an historical science, evolutionary theory is particularly vulnerable to Popperian falsificationism.
2. Additionally, some theories are complex enough that it is difficult to "predict" what should happen. Economics in particular in the social sciences has very clear, very simple mathematical models that simply do not permit of easy conclusions. If you look at the basic theories of standard economics, you would not predict a boom and bust economy. Marxian economics does. Score one for Marx and kick out the academics? Popper would have been the first to scorn the idea, as evidenced by his membership in the Mont Pelerin Society with the likes of Friedrich Hayek. No, there are a panoply of ad hoc explanations, auxiliary hypotheses, etc. Marxian economics of course has its own difficulties of this kind. The theory admits of moral factors, i.e., social custom and statutory law created by the activities of labor and capital, in the level of real wages. How then do you predict whether real wages inevitably decline over the secular trend? The answer, that you have to actually study real economies, globally and long-term, is not an evasion, marking an unscientific project. It is the mark of a real science that the theory should be extended and interpreted by real world information. Popper's insistence that the barebones of any theory have to be stuck too is remarkably metaphysical and dogmatic and all sorts of bad things that are opposed to real science. This is apparently the substance of the Duhem-Quine objection to falsificationism.
3. The more specific a theory is about its limitations, the better science it is. But I don't think this is what Popper means here. Suppose you have a theory that chieftains in technologically primitive societies compel their followers to increase production for their personal consumption and their ability to reward subordinates with the produce. Then by Popper's lights you are supposed to conclude that chieftains doing neither with the produce, but giving it away, even to non-subordinates, or even destroying the produce, is thereby impossible, in order to be doing good science. Frankly I think just making a simple example (by no means an absurd one either,) shows how wacky this is. He would then conclude that potlatch refutes the theory, and presumably the whole thing needs to be approached. Nonsense!
4. It occurs to me that I need to emphasize the "conceivable" is an equivocation. On reflection it occurs to me that Popper may have been trying to overextend the notion that, if a theory has two explanatory principles and the defender can switch at will from one to the other, then the critic cannot possibly refute the theory. (Psychoanalysis was probably the main offender in mind here.) The answer of course is that you refuse to accept this equivocation by the theory's proponent. You ask, in effect, exactly when is a cigar just a cigar? Then you see what the theory does and does not explain. Confusing this issue with the practical possibility of experiments may be useful in lambasting the historical sciences, but has no legitimate use in honest discourse.
5. Definitive experiments that refute hypothesese are much adored in science for good reason. They are also remarkably hard to come by. The numerous successes in evolutionary science in explaining facts in morphology, taxonomy, embryology and biogeography made Darwinism a successful scientific theory before someone contrived a controlled experiement that could refute it. Despite some facts that argued against it. By Popper's standards, evolutionary science was falsified. Again, the primary reason for this criterion appears to be to rule out by definition the very possiblity of an historical science. The problem with erecting the falsification standard is that it puts exceptions against mountains of examples following the rule without any standards as to why this should be so.
6. Rephrasing: There is a mountain of evidence confirming that people will claim to have private revelations from mystical sources and those who believe will discount any evidence disproving it. But this evidence should not count because we need to have a serious series of experiments showing that believers really will rationalize any disproofs of the revelation. Quite aside from the likelihood that detailed studies would show that some people do in fact reject the revelation, the injunction that we need to waste time on nonsense like this is far from a useful philosophy of science. Much less science. And, again, this is not a particularly absurd example!
7. All falsificationist/testbility perspectives founder on the inability to distinguish ad hoc assumptions from others. If you can't define ad hoc, the whole thing is a prime example of a theory for which there is no conceivable refutation!
8. Theories are scientific if they are materialistic; causal; consistent; comprehensive and confirmed by experience. Materialistic means that there are no supernatural agents or means. Causal means they identify cause and effect in an explanatory narrative, which includes identifying the role of random factors. Random factors may include repeated random occurrences whose effects can be probabilistically incorporated into the theory. Consistent means the elements of the theory are used in the same ways within the theory and the elements are consistent with other parts of nature as known. Comprehensive means that the theory aims to explain as much as possible, and to predict as specifically as possible. Confirmed by experience means historical experience as well as experiments.
1."It is easy to obtain confirmations, or verifications, for nearly every theory — if we look for confirmations."
This is very close to setting up a straw man, which is not a very good way to begin.
Every statistically controlled experiment or study sets up a bar for confirmation which in my opinion is not making it easy to find confirmation. We are apparently meant to assume the crudest and simplest (most naive) kind of activities, it appears.
2."Confirmations should count only if they are the result of risky predictions; that is to say, if, unenlightened by the theory in question, we should have expected an event which was incompatible with the theory — an event which would have refuted the theory."
Unenlightened by the germ theory, we should expect people to die, perhaps from cancer, without any signs of microbes. A risky prediction that the germ theory makes is that fatal diseases will be accompanied by germs, a risky prediction promptly disconfirmed by the autopsy of a victim of lung cancer. Ergo the germ theory is scientific, but wrong. This erroneous conclusion demanded by this principle of Popper’s suggests that no theory can be stretched beyond what it’s evidential foundation and internal logic permit, whether that allows "risky" conjectures or not. The failure of risky prediction may merely mean that the theory’s limits of validity have been reached.
3."Every "good" scientific theory is a prohibition: it forbids certain things to happen. The more a theory forbids, the better it is."
It is not clear how this is very different frm saying that the more a theory predicts, the better it is. The cell theory forbids that living things be composed of anything but cells or cell products. This formulation makes the cell theory sound like it is refuted by the abiogenetic origin of life.
Worse, this formulation forgets the most basic prohibition in science, the repudiation of the supernatural. Far better to say that every good scientific theory accepts the metaphysical postulates of philosophical materialism.
4."A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice."
This is just wrong. String theory or the multiverse concept may be wrong, and are as of this time immune to testing and refutation, but they are scientific in that they are deductions from well-tested scientific theories. Comparing the spectra of the Moon and green cheese to test the theory they are the same makes for a testable theory. The theory that there is however a Moon in a green cheese in another galaxy however is impossible to refute. According to this criterion, the first is a scientific
theory, but the latter is not.
5."Every genuine test of a theory is an attempt to falsify it, or to refute it. Testability is falsifiability; but there are degrees of testability: some theories are more testable, more exposed to refutation, than others; they take, as it were, greater risks."
The testability of theories lies partly in the phenomena they attempt to explain. This is not relevant to the scientificity of the theory. This criterion seems to be what I think they call a category mistake.
6."Confirming evidence should not count except when it is the result of a genuine test of the theory; and this means that it can be presented as a serious but unsuccessful attempt to falsify the theory. (I now speak in such cases of "corroborating evidence.")"
Again, disease germs are not found in all dead bodies. I suppose Virchow’s postulates could be rewritten as negative, disproof steps, but it is hard to see how this is useful. Worse, in complex phenomena, false negatives due to overextension of the theory will be far more likely. The real need for theories to be compatible with each other is entirely overlooked. (Incidentally, this is not really different from the insistence on the insistence on "risky" hypotheses.)
7."Some genuinely testable theories, when found to be false, are still upheld by their admirers — for example by introducing ad hoc some auxiliary assumption, or by reinterpreting the theory ad hoc in such a way that it escapes refutation. Such a procedure is always possible, but it rescues the theory from refutation only at the price of destroying, or at least lowering, its scientific status. (I later described such a rescuing operation as a "conventionalist twist" or a "conventionalist stratagem.")"
Only the simplest phenomena do not require numerous auxiliary hypotheses in theories. Further, life is ad hoc and it is not at all clear what possible criteria Popper has for labeling an auxiliary hypothesis ad hoc. Is the breaking of a natural damn an ad hoc hypothesis for the Channeled Scablands, which would otherwise refute theories of stratigraphy? A legitimate philosophy of science would be asking those questions, I thnk, not foolishly denying the necessity of auxiliary hypothese in perfectly good science.
8."We can sum up all this by saying that the criterion of the scientific status of a theory is its falsifiability, or refutability, or testability."
There are many trivial experiments. There are many false negatives from significant experiments. Experimental results must be interpreted in light of theories of many kinds of phenomena, and the experimental evidence for them, which means that scientificity also lies in the unitarity of explanations of nature. A parapsychologist can hypothesis ESP, make a risky prediction, test it, fail to refute it, yet we can confidently assert that sending information faster than light is impossible and that parapsychology therefore is not a scienctific enterprise. No matter how much it fits Popper’s criteria.
I understand that Popper once denied the theory of natural selection scientific status, which seems to me a natural conclusion of these criteria. Any experiments that falsify natural selection a la Popper really do tend to be rather trivial, don’t they?
Second thoughts (you knew this was coming didn't you?):
1. By the same token, it is easy to obtain falsifications for any theory, if we want to look for them. Sometimes it seems that those who adhere to a falsificationist perspective do so because it makes it easy to rule out tout court whole sciences without troubling to actually refute them. Popper personally, as The Open Society and Its Enemies shows, was primarily concerned to deny any social study the dignity of science. Creationists in my observation have very commonly adhered to a falsficationist perspective because, as an historical science, evolutionary theory is particularly vulnerable to Popperian falsificationism.
2. Additionally, some theories are complex enough that it is difficult to "predict" what should happen. Economics in particular in the social sciences has very clear, very simple mathematical models that simply do not permit of easy conclusions. If you look at the basic theories of standard economics, you would not predict a boom and bust economy. Marxian economics does. Score one for Marx and kick out the academics? Popper would have been the first to scorn the idea, as evidenced by his membership in the Mont Pelerin Society with the likes of Friedrich Hayek. No, there are a panoply of ad hoc explanations, auxiliary hypotheses, etc. Marxian economics of course has its own difficulties of this kind. The theory admits of moral factors, i.e., social custom and statutory law created by the activities of labor and capital, in the level of real wages. How then do you predict whether real wages inevitably decline over the secular trend? The answer, that you have to actually study real economies, globally and long-term, is not an evasion, marking an unscientific project. It is the mark of a real science that the theory should be extended and interpreted by real world information. Popper's insistence that the barebones of any theory have to be stuck too is remarkably metaphysical and dogmatic and all sorts of bad things that are opposed to real science. This is apparently the substance of the Duhem-Quine objection to falsificationism.
3. The more specific a theory is about its limitations, the better science it is. But I don't think this is what Popper means here. Suppose you have a theory that chieftains in technologically primitive societies compel their followers to increase production for their personal consumption and their ability to reward subordinates with the produce. Then by Popper's lights you are supposed to conclude that chieftains doing neither with the produce, but giving it away, even to non-subordinates, or even destroying the produce, is thereby impossible, in order to be doing good science. Frankly I think just making a simple example (by no means an absurd one either,) shows how wacky this is. He would then conclude that potlatch refutes the theory, and presumably the whole thing needs to be approached. Nonsense!
4. It occurs to me that I need to emphasize the "conceivable" is an equivocation. On reflection it occurs to me that Popper may have been trying to overextend the notion that, if a theory has two explanatory principles and the defender can switch at will from one to the other, then the critic cannot possibly refute the theory. (Psychoanalysis was probably the main offender in mind here.) The answer of course is that you refuse to accept this equivocation by the theory's proponent. You ask, in effect, exactly when is a cigar just a cigar? Then you see what the theory does and does not explain. Confusing this issue with the practical possibility of experiments may be useful in lambasting the historical sciences, but has no legitimate use in honest discourse.
5. Definitive experiments that refute hypothesese are much adored in science for good reason. They are also remarkably hard to come by. The numerous successes in evolutionary science in explaining facts in morphology, taxonomy, embryology and biogeography made Darwinism a successful scientific theory before someone contrived a controlled experiement that could refute it. Despite some facts that argued against it. By Popper's standards, evolutionary science was falsified. Again, the primary reason for this criterion appears to be to rule out by definition the very possiblity of an historical science. The problem with erecting the falsification standard is that it puts exceptions against mountains of examples following the rule without any standards as to why this should be so.
6. Rephrasing: There is a mountain of evidence confirming that people will claim to have private revelations from mystical sources and those who believe will discount any evidence disproving it. But this evidence should not count because we need to have a serious series of experiments showing that believers really will rationalize any disproofs of the revelation. Quite aside from the likelihood that detailed studies would show that some people do in fact reject the revelation, the injunction that we need to waste time on nonsense like this is far from a useful philosophy of science. Much less science. And, again, this is not a particularly absurd example!
7. All falsificationist/testbility perspectives founder on the inability to distinguish ad hoc assumptions from others. If you can't define ad hoc, the whole thing is a prime example of a theory for which there is no conceivable refutation!
8. Theories are scientific if they are materialistic; causal; consistent; comprehensive and confirmed by experience. Materialistic means that there are no supernatural agents or means. Causal means they identify cause and effect in an explanatory narrative, which includes identifying the role of random factors. Random factors may include repeated random occurrences whose effects can be probabilistically incorporated into the theory. Consistent means the elements of the theory are used in the same ways within the theory and the elements are consistent with other parts of nature as known. Comprehensive means that the theory aims to explain as much as possible, and to predict as specifically as possible. Confirmed by experience means historical experience as well as experiments.
Saturday, July 21, 2012
Natural Selection and Science as Prediction
Professor Steven Novella in his blog Neuralogica posted on a blogosphere controversy with one Egnor. Along the way he matter of factly announced that science was merely models useful for prediction, not about what's "correct," which in this context plainly meant corresponding to reality, i.e., true. This notion, in relation to natural selection, seems worthy of comment, on his comments section and here.) Post edited from the Neuralogica blog.
The principle of common descent would in another time or field of science would probably have been called a “law.” Scientific laws are commonly described as descriptions or generalizations about how things work in nature. Common descent was established on a mass of observations from morphology and embryology, and later confirmed further by genetic data. Scientific laws may be refined or possibly even wholly refuted by later observations. For instance, lateral gene transfer in bacteria seems to justify a refinement in the doctrine of common descent. There are antecedents to this principle, for instance, the cell theory, which implicitly requires that all changes in descent be physically possible for cells to carry out. And there are consequences too, such as that new species must come from old species. But is it really useful or enlightening to call these predictions?
Natural selection, on the other hand, is what some would call a theory, a scientific explanation, although I gather others would define “theory” as an algorithm(or verbal/conceptual equivalent) for generating predictions. In that case, this link [available in Prof. Novella's Neuralogica blog, July 19, 2012] says that Popper’s claim is that natural selection, equating adaptation to fitness, is non-predictive because all organisms must be adapted to their environments, else they would be extinct. The rebuttal is that 1) the unfit are extinct 2) physically impossible changes will not occur along the chain of common descent and 3) new species descend from old species.
Note that 1) is merely a restatement, not a prediction while 2) & 3) are trivial “predictions,” because they are not unique to the theory of natural selection. At this point, the link goes on to explain that fitness is defined causally, functionally, statistically a posteriori, not logically and semanticaly a priori. And besides that, fitness is not determininistic but dispositional. What is not clear is how fitness being those things makes it possible to make predictions. There have been a number of experiments that have successfully tested predictions about natural selection’s effects on gene frequencies but it seems that the difficulties in defining fitness in a way that you can predict/control makes them the exception rather than the rule in evolutionary science.
The thing worth thinking about, is that Darwin provided masses of evidence in favor of natural selection decades before experiments that teased out a prediction could be performed. Science since has provided masses more. But they weren’t predictions. [Omitted from comments to avoid pointless offense: The conclusion that Darwin wasn't doing much useful science because he didn't make many specific predictions, or propose many experiments, much less perform them, is demanded by the science as prediction perspective. Yet, it is nuts to deny Darwin was overwhelmingly right then, except for the modifications imposed later by a greater understanding of genetics. But the modern synthesis did not refute Darwin. An even greater understanding of modern genetics, as in the comprehension of the neutrality of so many mutations, is tending to modify the relative importance of natural selection in novel speciation, but is not "refuting" Darwin.]
You can use natural selection to explain vestigial organs. An organ is no longer adaptive, nature selects agains the waste of resources for it. The mechanics of genetics may not permit an easy way to simply erase the organ, but the slow increment of genetic changes diverts resources from the less fitting organ, it gets smaller and smaller, that is, vestigial. As the resources diverted become less cumbersome, however, the intensity of selection pressure becomes less and less. The vestigial organ can then survive indefintiely until the vagaries of genetic change do possibly succeed in erasing the last trace. Natural selection (particularly gene-selection) says traits are adaptive, increase fitness. We can explain fitness-decreasing vestigial organs as above, using supplementary hypotheses and contingencies that explain away the violation of this prediction.
We cannot predict which organs will become vestigial; we cannot predict which will finally disappear; we cannot predict for which a new function might be found; we can not statistically predict incidence of vestigialization, time for vestigialization, rates of vestigialization or intensity of natural selection against vestigial organs. But, rather than throw up our hands, isn’t the real clarification, not that natural selection is scientific because it is predictive, but, because it is explanatory of massive amounts of data. Charles Darwin made a convincing case for natural selection before the experiments. And the kind of evidence he presented has only been added to.
Even more to the point, if there are experiments confirming predictions of natural selection about speciation (instead of change in gene frequencies,) they are a well kept secret. I suppose it is likely that eventually science will find a way to conduct such experiments. But even if no one were ever ingeniuous enough to find the way, we already have quite a bit of evidence showing that natural selection is a major factor in novel speciation, and overwhelming evidence it is the major factor in maintaining species morphology (the forgotten aspect of speciation?) Is throwing out a lot of straw about predictions inviting the Egnors to make straw men?
[Addendum: The old canard that "natural selection is survival of the fittest" is a tautology is indeed a canard. First, technically, the whole statement is merely a definition, and definitions are themselves a kind of tautology. They are not logical arguments, but explanations. The phrase "survival of the fittest" can be interpreted as a tautology by insisting that you can't define fittest in any way other than by survival. Not true, and insofar as the link points this out, it is correct.
Second, the second problem with the capsule statement of natural selection lies in the unconscious assumption that to be a valid scientific theory, it must be predictive. And natural selection is not, repeat, not predictive in any meaningful sense. It is powerfully explanatory, as dwelt on above. Post hoc, it is in principle possible to define fitness meaningfully. An often unacknowledged consequence of this unpredictability means that there is no way to retrodict the past. All reconstructions in evolutionary history are open to the difficulties of all historical reconstructions. And all the quarrels about relative importance in principle of supplementary assumptions and ad hoc contigencies, too. As much tedious work and dispute as this enjoins on evolutionary scientists, this is far more devastating to those who would find necessity or inevitability or plan or guidance or God in evolutionary history.
All versions of theistic evolution, sophisticated or crude, are refuted by the inability of natural selection to predict. Or so I think.
Third, if you want to find a logical problem in arguments over evolutionary theory, consider the criticism that there are "gaps" in the fossil record. Defining a "gap" is as difficult as defining a "heap.
We could think of a gap as an inverted heap after all. The difficulty of defining a heap is even called a paradox! The creationists have for decades proffered a logical paradox as a criticism of legitimate science! Technically, I suppose, they could proffer simultaneously an empirical/practical definition of gap, and at least be making an honest argument. Until they do, just remember all arguments about gaps are logically flawed! (No, I am not touching the question of how useful formal logic is in doing science.)]
The principle of common descent would in another time or field of science would probably have been called a “law.” Scientific laws are commonly described as descriptions or generalizations about how things work in nature. Common descent was established on a mass of observations from morphology and embryology, and later confirmed further by genetic data. Scientific laws may be refined or possibly even wholly refuted by later observations. For instance, lateral gene transfer in bacteria seems to justify a refinement in the doctrine of common descent. There are antecedents to this principle, for instance, the cell theory, which implicitly requires that all changes in descent be physically possible for cells to carry out. And there are consequences too, such as that new species must come from old species. But is it really useful or enlightening to call these predictions?
Natural selection, on the other hand, is what some would call a theory, a scientific explanation, although I gather others would define “theory” as an algorithm(or verbal/conceptual equivalent) for generating predictions. In that case, this link [available in Prof. Novella's Neuralogica blog, July 19, 2012] says that Popper’s claim is that natural selection, equating adaptation to fitness, is non-predictive because all organisms must be adapted to their environments, else they would be extinct. The rebuttal is that 1) the unfit are extinct 2) physically impossible changes will not occur along the chain of common descent and 3) new species descend from old species.
Note that 1) is merely a restatement, not a prediction while 2) & 3) are trivial “predictions,” because they are not unique to the theory of natural selection. At this point, the link goes on to explain that fitness is defined causally, functionally, statistically a posteriori, not logically and semanticaly a priori. And besides that, fitness is not determininistic but dispositional. What is not clear is how fitness being those things makes it possible to make predictions. There have been a number of experiments that have successfully tested predictions about natural selection’s effects on gene frequencies but it seems that the difficulties in defining fitness in a way that you can predict/control makes them the exception rather than the rule in evolutionary science.
The thing worth thinking about, is that Darwin provided masses of evidence in favor of natural selection decades before experiments that teased out a prediction could be performed. Science since has provided masses more. But they weren’t predictions. [Omitted from comments to avoid pointless offense: The conclusion that Darwin wasn't doing much useful science because he didn't make many specific predictions, or propose many experiments, much less perform them, is demanded by the science as prediction perspective. Yet, it is nuts to deny Darwin was overwhelmingly right then, except for the modifications imposed later by a greater understanding of genetics. But the modern synthesis did not refute Darwin. An even greater understanding of modern genetics, as in the comprehension of the neutrality of so many mutations, is tending to modify the relative importance of natural selection in novel speciation, but is not "refuting" Darwin.]
You can use natural selection to explain vestigial organs. An organ is no longer adaptive, nature selects agains the waste of resources for it. The mechanics of genetics may not permit an easy way to simply erase the organ, but the slow increment of genetic changes diverts resources from the less fitting organ, it gets smaller and smaller, that is, vestigial. As the resources diverted become less cumbersome, however, the intensity of selection pressure becomes less and less. The vestigial organ can then survive indefintiely until the vagaries of genetic change do possibly succeed in erasing the last trace. Natural selection (particularly gene-selection) says traits are adaptive, increase fitness. We can explain fitness-decreasing vestigial organs as above, using supplementary hypotheses and contingencies that explain away the violation of this prediction.
We cannot predict which organs will become vestigial; we cannot predict which will finally disappear; we cannot predict for which a new function might be found; we can not statistically predict incidence of vestigialization, time for vestigialization, rates of vestigialization or intensity of natural selection against vestigial organs. But, rather than throw up our hands, isn’t the real clarification, not that natural selection is scientific because it is predictive, but, because it is explanatory of massive amounts of data. Charles Darwin made a convincing case for natural selection before the experiments. And the kind of evidence he presented has only been added to.
Even more to the point, if there are experiments confirming predictions of natural selection about speciation (instead of change in gene frequencies,) they are a well kept secret. I suppose it is likely that eventually science will find a way to conduct such experiments. But even if no one were ever ingeniuous enough to find the way, we already have quite a bit of evidence showing that natural selection is a major factor in novel speciation, and overwhelming evidence it is the major factor in maintaining species morphology (the forgotten aspect of speciation?) Is throwing out a lot of straw about predictions inviting the Egnors to make straw men?
[Addendum: The old canard that "natural selection is survival of the fittest" is a tautology is indeed a canard. First, technically, the whole statement is merely a definition, and definitions are themselves a kind of tautology. They are not logical arguments, but explanations. The phrase "survival of the fittest" can be interpreted as a tautology by insisting that you can't define fittest in any way other than by survival. Not true, and insofar as the link points this out, it is correct.
Second, the second problem with the capsule statement of natural selection lies in the unconscious assumption that to be a valid scientific theory, it must be predictive. And natural selection is not, repeat, not predictive in any meaningful sense. It is powerfully explanatory, as dwelt on above. Post hoc, it is in principle possible to define fitness meaningfully. An often unacknowledged consequence of this unpredictability means that there is no way to retrodict the past. All reconstructions in evolutionary history are open to the difficulties of all historical reconstructions. And all the quarrels about relative importance in principle of supplementary assumptions and ad hoc contigencies, too. As much tedious work and dispute as this enjoins on evolutionary scientists, this is far more devastating to those who would find necessity or inevitability or plan or guidance or God in evolutionary history.
All versions of theistic evolution, sophisticated or crude, are refuted by the inability of natural selection to predict. Or so I think.
Third, if you want to find a logical problem in arguments over evolutionary theory, consider the criticism that there are "gaps" in the fossil record. Defining a "gap" is as difficult as defining a "heap.
We could think of a gap as an inverted heap after all. The difficulty of defining a heap is even called a paradox! The creationists have for decades proffered a logical paradox as a criticism of legitimate science! Technically, I suppose, they could proffer simultaneously an empirical/practical definition of gap, and at least be making an honest argument. Until they do, just remember all arguments about gaps are logically flawed! (No, I am not touching the question of how useful formal logic is in doing science.)]
Friday, July 20, 2012
What is Science?
Science, from the Latin word scientia, is knowledge. It is what people have learned. It is the way that people acquire knowledge (this is often separately dubbed "the scientific method.") It is what people called scientists do.
PS Reviewing after resumption, I note that I should have emphasized that the people called scientists are paid to do what they call science.
PS Reviewing after resumption, I note that I should have emphasized that the people called scientists are paid to do what they call science.
Resumption
It appears that stray people are viewing the blog. I think it is largely random searches. Certainly I haven't publicized the existence of the blog, which was an experimental diary with a password and greater physical ease. Deletion of course was a reasonable option, but for now I will resume postings ad hoc. There will still be no publicization. Nor will there be links, to prevent link tracking publicizing the blog, which will still exist primarily for self-clarification (simulated as blogging.)
It appears that stray people are viewing the blog. I think it is largely random searches. Certainly I haven't publicized the existence of the blog, which was an experimental diary with a password and greater physical ease. Deletion of course was a reasonable option, but for now I will resume postings ad hoc. There will still be no publicization. Nor will there be links, to prevent link tracking publicizing the blog, which will still exist primarily for self-clarification (simulated as blogging.)
Sunday, April 18, 2010
Finishing Up (Barring an unfortunate turn of events)
Michael Ruse felt very martyred at a November 2006 conference at the Salk Institute.
(The other Skeptical Inquirer article that inspired an effort at blogging.) Part of his problem is his belief that the objection to religion is "dogmatism, refusal to listen to others, a contempt for nonbelievers, a feeling that they alone have the truth..." Basically, anyone who doesn't meet his personal moral standards for intellectual discourse. Intellectual snobbery is not actually a moral principle. The problem with religion is that it's not true. Therefore believing in it requires asserting falsehoods as true. Often the biggest falsehood is that an act of will to repeatedly assert falsehoods as truth is belief. Turning the critique of religion into a critique of personalities ignores the social aspects of religion and questions of philosophical truth, in favor of self assertion.
There's worse: Ruse declared "I fully accept that many believers are good because of their beliefs." Rationally this includes Scientology, the Aetherians, astrologers, snake handlers, peyote cults, Santeria animal sacrifice etc. ad nauseam. Ruse of course is a professional philosopher. As such he was surely trained in logic. Now as I recall the contrapositive is equivalent to the proposition. Rephrasing, the proposition If p, then q) reads: "If some people believe in religion, then they will be morally good." The contrapositive (If not p, then not q) reads: " If some people do not believe in religion, then they will be morally bad." Ruse has formally justified religious bigotry as a moral principle. Counterposing his personal taste in morals so that he can pick and choose which religions are the good making ones avails nothing. The man is worse than a fool, he's a hypocrite. He merely wants to use science as a club against religions he doesn't like. Science rejects them all, because we know now they're all wrong.
As part of the assault on atheism, in behalf of said snobbery, Michael Shermer devised some principles he title "Rational Atheism." The first is that atheism, being against something, is a movement doomed to fail. Atheism is a doctrine, not a movement, however, so this spectacularly misses the point. Marxists and Objectivists are both atheists. They are not in the same movement! Besides, atheism is not just a self identification. The mass of nonbelievers, including those in the pulpit, almost certainly far outnumbers the believers.
The second principle holds that atheists should merely champion science and reason. Then he quotes Charles Darwin. This is astounding, since the religious attacks on evolution have successfully fought off the supposedly superior positive approach quite successfully, so that evolutionary teaching is still endangered, after over a century of positivity. The principle is really that failure is preferable to being socially gauche enough to argue religion.
The third is to blame atheists for the hostility of the religious. Since practically every atheist has suffered massive provocation, this merely proves Shermer, safely ensconced in his little social cocoon, enjoys sneering at the losers who haven't succeeded in finding their own.
The fourth is some tripe about not prejudging religious believers. Again, the religious did not need a moment's provocation. Their hostility is not a response. Any such implication is a vicious lie.
Last, promote freedom of belief and disbelief. This is political piety and wholly irrelevant.
Michael Ruse felt very martyred at a November 2006 conference at the Salk Institute.
(The other Skeptical Inquirer article that inspired an effort at blogging.) Part of his problem is his belief that the objection to religion is "dogmatism, refusal to listen to others, a contempt for nonbelievers, a feeling that they alone have the truth..." Basically, anyone who doesn't meet his personal moral standards for intellectual discourse. Intellectual snobbery is not actually a moral principle. The problem with religion is that it's not true. Therefore believing in it requires asserting falsehoods as true. Often the biggest falsehood is that an act of will to repeatedly assert falsehoods as truth is belief. Turning the critique of religion into a critique of personalities ignores the social aspects of religion and questions of philosophical truth, in favor of self assertion.
There's worse: Ruse declared "I fully accept that many believers are good because of their beliefs." Rationally this includes Scientology, the Aetherians, astrologers, snake handlers, peyote cults, Santeria animal sacrifice etc. ad nauseam. Ruse of course is a professional philosopher. As such he was surely trained in logic. Now as I recall the contrapositive is equivalent to the proposition. Rephrasing, the proposition If p, then q) reads: "If some people believe in religion, then they will be morally good." The contrapositive (If not p, then not q) reads: " If some people do not believe in religion, then they will be morally bad." Ruse has formally justified religious bigotry as a moral principle. Counterposing his personal taste in morals so that he can pick and choose which religions are the good making ones avails nothing. The man is worse than a fool, he's a hypocrite. He merely wants to use science as a club against religions he doesn't like. Science rejects them all, because we know now they're all wrong.
As part of the assault on atheism, in behalf of said snobbery, Michael Shermer devised some principles he title "Rational Atheism." The first is that atheism, being against something, is a movement doomed to fail. Atheism is a doctrine, not a movement, however, so this spectacularly misses the point. Marxists and Objectivists are both atheists. They are not in the same movement! Besides, atheism is not just a self identification. The mass of nonbelievers, including those in the pulpit, almost certainly far outnumbers the believers.
The second principle holds that atheists should merely champion science and reason. Then he quotes Charles Darwin. This is astounding, since the religious attacks on evolution have successfully fought off the supposedly superior positive approach quite successfully, so that evolutionary teaching is still endangered, after over a century of positivity. The principle is really that failure is preferable to being socially gauche enough to argue religion.
The third is to blame atheists for the hostility of the religious. Since practically every atheist has suffered massive provocation, this merely proves Shermer, safely ensconced in his little social cocoon, enjoys sneering at the losers who haven't succeeded in finding their own.
The fourth is some tripe about not prejudging religious believers. Again, the religious did not need a moment's provocation. Their hostility is not a response. Any such implication is a vicious lie.
Last, promote freedom of belief and disbelief. This is political piety and wholly irrelevant.
Subscribe to:
Posts (Atom)