May 2004. Disclaimer: Typos and blatant mistakes abound. You've been warned. ========== 1. What is a law of science? How do laws of science differ from other types of generalizations? How does science go about determining whether a generalization is a law? Laws of science are generalizations based on observations, but they are more than generalizations. Laws are (perhaps) necessary generalizations which must be true, support counterfactuals, point at underlying causal structures/mechanisms, etc. One method for determining whether a generalization is a law is (following Popper), to attempt to falsify the law by finding counterexamples. Note: laws of science are revisable, laws are often assessed on non-observational grounds. Laws should be as concise and universal as possible. Laws of science are statements expressing regularity, but not all statements of regularity are laws. Laws of science are (according to some) generalization which are (within a range of conditions) necessarily (approximately) true. If this is the case, than laws support counterfactuals. They can be projected. Law are falsifiable (Popper); they can be falsified or confirmed by experiment. Laws are well-tested. Laws are used to explain the facts which are already known and to predict new facts. Laws play a crucial role in the deductive-nomological model of explanation (Hempel). Laws (perhaps) point to causal connections; the law of gravity doesn't just generalize other laws/observations, it seems to be the underlying cause of those observations. Laws state universal regularities which are not accidental generalizations; they support counterfactuals and allow for reliable predictions. There are no exceptions; they hold everywhere. "The necessity of laws is related to the existence of stable mechanisms that generate the phenomena they describe. We must test and see if such mechanisms exist .... A claim that a certain statement is a Law is vulnerable to the discovery that the generative mechanism which we thought existed and [had been correctly represented in our model] does not.... A law is universal and necessary." (Laws of Nature, Black Comp, p 222) Compare: All solid spherical masses of pure gold weigh less than 100,000 kg. All solid spherical masses of pure plutonium weigh less than 100,000 kg. Both are true generalizations, but the former is only accidentally true while the latter is nomologically true (law-like). Examples of laws of science: laws of thermodynamics, Kepler's laws, Newton's laws of motion, Ohm's law See: Rosenberg #2, Black Comp #19,33, Rout #3-7, Carnap p3+ http://www.utm.edu/research/iep/l/lawofnat.htm (long) ========== 2. One often speaks of the laws of physics, but less often of the laws of geology or physiology. What role do laws play in the various sciences? Are the so-called laws of economics or psychology the same sort of thing as the laws of physics? Laws pick out regularities (and/or causal processes) and point to generalizations, allowing us to make reliable explanations and predictions. The laws of economics are not the same kind of laws as those of physics. The latter are natural or physical laws and as such express some sort of physical necessity (they are not accidental generalizations). The laws of economics are of use in making predictions (under certain circumstances), but they are not natural laws. The laws of economics are not the same kind of thing as the laws of physics. But, the laws of economics are to economics as the laws of physics are to physics. Both laws are generalizations which allow for making predictions. However, only physical laws express (physical) necessity; economic laws instead express (economic) necessity. Some things are physically, but not economically possible. Laws of physics seem to be concise; I'm not sure if laws of economics are. Law of supply and demand: in equilibrium, prices are determined so that demand equals supply; changes in prices thus reflect shifts in the demand or supply curves. See: Debates #7-8 ========== 3. In a passage that has provoked centuries of controversy, Newton remarks, "I have not as yet been able to deduce from phenomena the reasons for these properties of gravity, and I do not feign hypotheses. For whatever is not deduced from the phenomena must be called a hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy." What is Newton claiming here? Is his claim tenable? This passage is often attacked because it seems to many that the Principia is full of hypotheses. However, Newton means something very specific by hypotheses (not deduced from phenomena) and feign (fingo). Newton is claiming that his law of gravity is not a hypothesis. It is more certain because it is deduced from phenomena. Newton is talking about speculation beyond the data. The data do not suggest the reasons for which gravity behaves the way it does, merely the fact that it does so. Newton is claiming that experimental philosophy has no place for hypotheses which do not follow from the phenomena. That the world behaves as if there is gravity (inverse square force) follows directly from the motions Newton studied. But what causes gravity (what it is), does not. Perhaps where Newton says hypothesis we would now say conjecture. Newton in a letter to Cotes: "As in Geometry, the word Hypothesis is not taken in so large a sense as to include the Axiomes & Postulates, so in Experimental Philosophy it is not to be taken in so large a sense as to include the first Principles or Axiomes which I call the laws of motion. [These] are deduced from Phaenomena & made more general by Induction: which is the highest evidence that a Proposition can have in this philosophy.... The word Hypothesis is here used by me to signify only such a Proposition as is not a Phaenomenon nor deduced from any Phaenomena but assumed or supposed without any experimental proof." Westfall: "Against what he saw as the uncontrolled rationalism of Cartesian natural philosophy, he insisted on the primacy of empirical experimental data in the establishment of scientific truth. Perhaps his most repeated words, 'Hypotheses non fingo' (I do not feign hypotheses), come from a discussion of gravity in the General Scholium that he added to the second edition of the Principa. In this passage Newton asserted that natural phenomena establish the fact of universal gravitation. He refused, however, to compromise the solidity of that demonstration with speculations about the cause of gravity.... His insistence on the distinction between matters he took to be mathematical demonstrations based on empirical evidence and speculations that went beyond such matters constituted the heart of his methodological stance." McMullin: "Newton's reluctance to allow hypothesis as part of science proper was a step backwards, looked on from the perspective of a later day. The difficulty he encountered in construing gravity in explanatory terms led him to bracket the methodological issues raised by causal explanation; he could then represent the derivations of the fundamentals of his mechanics as 'deduction' from the phenomena, subsequently made general by 'induction'. Such a science wold consist of 'laws', empirically determined regularities." Mill: "The existence of the ether still rests on the possibility of deducing from its assumed laws a considerable number of actual phenomena.... An hypothesis of this kind is not to be received as probably true because it accounts for all the known phenomena, since this is a condition sometimes fulfilled tolerably well by two conflicting hypotheses." "Mills attitude to the use of hypotheses in science was ambivalent. On the other hand, his abhorrence of anything which smacked remotely of a priorism made him unwilling to countenance the admission to a process of reasoning of any proposition which could not be rigorously confirmed by observation or the inductive methods." Shapiro: "He believed that he could establish a more certain science both by developing mathematical theories and by basing his theories on experimentally discovered properties. To establish a more certain science, Newton insisted that one must 'not mingle conjectures with certainties.'... Newton continually railed against hypotheses, that is, conjectural causal explanation. His condemnations of hypotheses are always aimed at preserving the certainty of scientific principles rather than objecting to the use of hypotheses in themselves. Newton held that hypotheses without any experimental support whatever, such as Cartesian vortices, had no place in science, but those based on some experimental evidence, though insufficient to establish them as demonstrated principles, could be used to understand properties already discovered and to suggest new experiments.... Newton believed that by formulating his theories in terms of experimentally observed properties, or principles deduced form them, without any causal explanations (hypotheses) of those properties, he could develop a more certain science." Harper: "One of the Newton's most controversial claims is that he 'deduced' the law of universal gravity from phenomena of orbital motion. In particular, a tradition that began with Duhem and continued with Popper and then Lakatos has argued that this claim is at best misleading and at worst a subterfuge. They insist that only a hypothetico-deductive construal of Newton's evidence for universal gravity makes sense.... I will argue that his argument from phenomena to universal gravitation illustrates a general methodology in which phenomena constrain theory to approximations established by measuring parameters." See: Principia p943, translators notes p275, Duhem, Cambridge 227+,174+, Black Comp p326,555,321 ========== 4. "The principal task of the philosophy of science is the rational reconstruction of the history of science." What are the implications of this view for the relationship between philosophy of science and history of science? Is this what the relationship between the two disciplines ought to be? "On Lakatos's account the testing of a philosophical theory requires empirical historical research.... Lakatos's philosophy was intended to be a reasoned exchange between methodological theory and the best scientific practice.... History had something to learn from philosophy. Lakatos claimed that 'all historians of science who hold that the progress of science is progress in objective knowledge, use, willy-nilly some rational reconstruction'. A 'rational reconstruction' is a historical narrative in which events are explained by reference to some methodological pattern.... All historical writing had some theoretical bias..... A historian of science who regards the history of science as largely a story of advancing knowledge must be committed to some normative conception of the scientific.... It sounds as if the history and philosophy of science are two aspects of a single subject..... Philosophers need to learn to do philosophy by writing case studies in the history of science, and historians need to become more self-aware regarding their theoretical commitments. It will then be possible for the history and philosophy of science to become a single seamless discipline, with no hard distinction between historical fact and philosophical theory.... Are history and philosophy one and the same? Would an institutional union be well advised? Kuhn suggested that the answer to both questions is 'No.' He argued the point by reporting his experience of leading seminars to graduate students of history and philosophy. 'It was often difficult to believe that both had been engaged with the same texts'. The philosophy students tended to produce readings which depended on subtle distinctions which were invisible to the history students because they were not present in the text.... Historians drew on a wider range of supplementary material.... Philosophy and history have different goals. Historians want to understand how this individual came to believe that specific theory. Philosophers tend to be interested in the merits of the theory as such, so it is entirely natural for them to construct a rigorous, decontextualized version of whatever they are asked to discuss.... They require mutually exclusive intellectual habits and attitudes. One cannot do both at once." (Black Comp, History, p157-8) Philosophers don't write good history because they don't judge a narrative on its own terms, but on philosophical lessons. Philosophers raid the archives for evidence of their favorite philosophical theses. As such, historians may be tempted to ban philosophers from history, but they should instead recognize the philosophically motivated historical narrative as a distinct genre. The role of history in philosophy of science: a source of philosophical problems and questions; a standard against which to test philosophical theories; provides material for philosophical narratives; allows philosophers to learn science through a critical distance. Historians object that Lakatos's "rational reconstructions" deform history. "The legitimate, sure, and fruitful method of preparing a student to receive a physical hypothesis is the historical method. To retrace the transformations through which the empirical matter accrued while the theoretical form was first sketched.... To give the history of a physical principle is at the same time to make a logical analysis of it. The criticism of the intellectual processes that physics puts into play is related indissolubly to the exposition of the gradual evolution by which deduction perfects a theory and makes of it a more precise and better-ordered representation of laws revealed by observation.... History thus maintains [the physicist] in that state of perfect equilibrium in which he can soundly judge the aim and structure of physical theory." (Duhem p 268-70) Philosophers had to take an interest in science to argue against Kuhn. Rational reconstructionism dominated the philosophy of science until the 1960s. In 1962, Thomas Kuhn's, The Structure of Scientific Revolutions challenged rational reconstruction with a historicist theory of the history of scientific ideas. Kuhn saw science as progressing through a discontinuous series of qualitatively distinct "paradigms," which succeeded each other through sociological and political struggle.2 Rational reconstruction's last important sponsor, Imre Lakatos, used it to oppose Kuhn's theory of scientific revolutions, which Lakatos called irrational. Lakatos, who was not a positivist, developed a theory of scientific progress that gave a major role to rational reconstruction. Philosophers can determine whether science progressed during a historical era, he argued, by comparing the actual scientific work to a rationally reconstructed schemata of the research programs relevant a set of phenomena. When historical scientists were producing work that moved closer to the rationally reconstructed axiomatic schemes (for example, by incorporating more cases under a single law), then there was scientific progress. For Lakatos, it was useful to make this comparison between the rationally reconstructed research program and the actual work conducted by scientists, because the scientists were (whether they were aware of it or not) working toward that scheme. From this point of view, the rationally reconstructed research program is the context in which the actual history of science occurred and makes it meaningful See: Black Comp #23,32 Lakatos, Kuhn intro, Duhem p268+ http://www.info.human.nagoya-u.ac.jp/~iseda/works/general_field_exam.html http://www.horuspublications.com/guide/cm107.html ========== 5. "The more carefully they [historians] study, say, Aristotelian dynamics, phlogistic chemistry, or caloric thermodynamics, the more certain they feel that those once current views of nature were, as a whole, neither less scientific nor more the product of human idiosyncrasy than those current today." Do scientific views current today have any claim to being more scientific or less the product of human idiosyncrasy than those Kuhn singles out from the past? If none, can science legitimately claim epistemic authority? This sounds like what is known as the argument from pessimistic meta-induction (or something like that). The (now known false) theories of the past seemed (at the time) to be just as true as today's theories (now seem). We then have reason to believe that today's theories seem true, but will be shown false in the future. Many arguments against this rely on the claim that science is improving/progressing and that the succession of theories are converging on truth. The fear, as I see, it is something like: We've been wrong in the past when we thought we were right. So we're likely wrong now even though we think we're right. This assumes that the (status of views of the) present is like the (status of the view of the) past, but it might be that the method of science and its results are improving/evolving. Still, it seems that some of our current theories will be shown to be false. Whether or not science can claim epistemic authority, it seems to be the best we've got. Or possibly, they weren't really doing science (following the method), but maybe we are. Kuhn: If these out-of-date beliefs are to be called myths, then myths can be produced by the same sorts of methods and held for the same sorts of reasons that now lead to scientific knowledge. If, otoh, they are to be called science, then science has included bodies of belief quite incompatible with the ones we hold today.... Observation and experience cannot alone determine a particular body of such belief. An apparently arbitrary element, compounded of personal and historical accident, is always a formative ingredient of the beliefs espoused by a given scientific community at a given time. (Kuhn, 2-4) Kuhn is often taken as showing that science has no epistemic superiority over other disciplines with competing paradigms. Past scientific theories have generally turned out to be false, so by induction our current theories are (likely) false and we should abandon realism for instrumentalism. Laudan arguing against convergent realism: convergent realism says scientific theories are typically approximately true and more recent theories are closer to the truth than older ones ... the success of science is only explainable by realism. A theory is successful so long as it has worked well in explanations and predictions. There are many past theories which were once successful and well confirmed but which contain central terms which we now believe were non-referring (caloric theory of heat, phlogiston theory, crystalline spheres, etc). It seems that false theories can have true consequences, be useful, etc. van Fraassen (constructive empiricism): "Any scientific theory is born into a life of fierce competition, a jungle red in tooth and claw. Only the successful theories survive -- the ones which in fact latched on to actual regularities in nature." Only successful theories have survived. What does it mean to be more scientific? See: Kuhn p2 etc, Black Comp Phil p 300, Rosenberg, Rout # 13-15, ========== 6. One might say that colors have been explained, but ghosts have been explained away. Aristotle considered telos ("final cause") or purpose as one of the four fundamental aitia or causes. Darwin's theory of evolution by natural selection is often said to provide a reduction of the apparent purpose in nature to purposeless mechanism. Is this explanation like the explanation of color or ghosts? Has Darwin shown that there is no purpose, or has he shown how to explain real purpose? Darwin gives us a new way of explain 'why' questions (purpose, intentionality, teleology). Evolution tells us what our purpose is: our purpose is survival. The worry is something like this (maybe): We think we (and our actions) have some final purpose/intention. But evolution says we act the way we do because of instinct/propensity in our genes. So our purpose can be explained by the fact that it in our genes (which came from our parents genes, their parents' genes...), in others, because it was the kind of trait that is successful and survived to be genetical encoded and transmitted. Because any (seemingly) purposeful action we can identify can be explained be inheritence/genetics, it seems like our actions follow directly from our nature, are automatic, and ad hoc. Why these particular behaviors? Because that's what the genes say. Why do the genes say that? Because their parents' genes, and their parents' genes.... Our final cause is to survive and pass on successful genes. Intelligent design. Telos or final cause -- the sake for which a thing is done; the final cause of a natural object is what lies at the end of the regular series of developmental changes it undergoes (the telos of a developing tiger is to be a tiger) Natural teleology: 1. goal-directed behavior (I did this in order to do that) 2. artifacts endowed with functions by organisms that design, manufacture, and use them to serve their goals (Tools) 3. features and parts of living things which have natural functions for their possessors (Organs) 4. social phenomena which have functions within social organizations " What is the difference between order and design? As a first stab, I would say that order is mere regularity, mere pattern; design reflects Aristotle's telos, an exploitation of order for a purpose, as in a cleverly designed artifact. The solar system exhibits stupendous order, but (apparently) it has no purpose - it is not for anything. An eye, in contrast, is for seeing. Before Darwin, the distinction was not always clearly marked, but Darwin suggested a division. Give me order and time, he said, and I will give you design - without the aid of mind. ... The answer, I think, is fear. They are afraid that the idea will not just explain but will explain away the minds and purposes and meanings that everyone holds dear; that the universal acid will pass through their most cherished monuments, dissolving them into an unrecognizable and unlovable puddle of scientistic destruction." Dennett http://pubs.socialistreviewindex.org.uk The key problem that Darwin addressed was that of design in nature. Philosophers from Aristotle to the theologian William Paley had pointed to the infinite number of ways in which the parts of the natural world seem to be designed to achieve certain ends. Thus, to use a standard example, the giraffe's long neck allows it to feed off the leaves of trees. Before Darwin, the usual way of explaining all these features was teleologically. A teleological explanation accounts for something in terms of the goal or purpose it serves (what Aristotle called its 'final cause'). But to identify a purpose is also to presume the existence of some agent whose purpose it was. In some cases this is quite unproblematic. We don't worry about saying that the purpose of a house is to provide shelter because we know that houses are built by human beings, organisms who are, among other things, capable of consciously selecting goals and acting in the light of them. But to discover purposes in nature is to invoke a super-agent, a creator -in other words, God. As Marx saw, Darwin's historic significance lay in the fact that he dethroned teleology from the privileged place that it had previously enjoyed in the explanation of nature in general and of living organisms in particular. In Dennett's words, 'Darwin explains a world of final causes and teleological laws with a principle that is, to be sure, mechanistic but - more fundamentally - utterly independent of "meaning" or "purpose".'13 This principle is natural selection. Natural selection allows Darwin, as Marx put it, to explain the 'rational basis' of teleology. All the apparent wonders of design - including the human mind and its creations - turn out to be the products of a mindless mechanical process. Dennett calls natural selection an 'algorithmic process': algorithms are formal procedures like long division which, whenever they are applied, can be guaranteed to produce certain results. He imagines Darwin saying: 'Give me Order,...and time, and I will give you Design. Let me start with regularity - the mere purposeless, mindless, pointless regularity of physics - and I will show you a process that eventually will yield products that exhibit not just regularity but purposive design'.16 Human beings are precisely such purposive designers, but they are also among the products of this process. Intentionality is something that gradually emerges through a series of intermediary stages, as species of organisms develop that have the ability to act on their environment in order to achieve certain purposes. In most cases the selection of these objectives and of the means required to attain them are just wired in: they are fixed in the genetic coding of the species. But in certain conditions, variations occur which confer selective advantages on organisms that have a far greater degree of flexibility in choosing goals and the means of attaining them. See: Dennett, Black Comp #71, http://pubs.socialistreviewindex.org.uk/isj71/darwin.htm http://faculty.washington.edu/smcohen/320/4causes.htm ========== 7. Atomic theory, quantum theory, Einstein's theory of general relativity, Maxwell's theory of electromagnetism, the "big bang" theory, and elasticity theory are just a handful of the logical structures which are called "theories". What exactly is a scientific theory? Theory -- principle formulated to account for observable phenomena; theory (syntactic) -- axiomatic system in which empirical generalizations are explained by derivation from theoretical laws; statements are fundamental theory (semantic) -- sets of models (definitions of relatively simple systems with some degree of applicability to the world); models are fundamental Scientific theories satisfy the following criteria: consistent, parsimonious, useful, empirically testable and falsifiable, based upon controlled repeated experiments, correctable and dynamic, progressive, tentative. According to the received (syntactic) view, a theory is a set of uninterpreted axioms in a specified formal language and a set of correspondence rules that provide a partial empirical interpretation in terms of observable entities and processes. A theory is true if and only if the interpreted axioms are all true.... On the semantic approach, a theory consists of a theoretical definition plus a number of theoretical hypotheses. The theory may be said to be true just in case all of its associated theoretical hypotheses are true. (Black Comp, p519) According to Duhem, A physical theory is not an explanation. It is a system of mathematical propositions, deduced from a small number of principles, which aim to represent as simply, as completely, and as exactly as possible a set of experimental laws. (Duhem, 19) Theories from which more empirical laws can be derived are generally stronger theories. Theories make it possible to derive/predict new laws which can be confirmed. (Carnap, 231) Theories are underlying principles which unify (otherwise seemingly-unrelated) empirical laws. (Carnap, 244) There are many alternatives to this answer, including the (now more common) semantic approach of model-based understanding (Beth, van Fraassen), where idealized theoretical models, not statements, are basic. Received view -- theories are linguistic structures which are given empirical content through correspondence rules. The model view -- theories specify or define abstract idealized systems. Models are structures that satisfy these specifications, and they correspond with real systems. Theories are systems or frameworks. Theories are testable, tested, confirmed for agreement with observation, well-supported by evidence, and play a role in explaining and predicting natural phenomena. Theories are established. They are/provide the best known explanations. Hawkings says good theories accurately describe a large class of observations on the basis of a model that contains only a few arbitrary elements and make definite predictions of future observations. Physical theories are always provisional and are disproved by finding observations to the contrary. Theories make claims about unobservables. Kuhn: theories are accepted as paradigms, they set the problems to be solved. Is there any difference between a theory and a paradigm? See: Blackwell Comp #73, Rosenberg #4, Rout, Carnap, Duhem p 19+, Black Guide #4, Kuhn? http://en.wikipedia.org/wiki/Scientific_theory http://atheism.about.com/library/FAQs/evo/blfaq_sci_theory.htm ========== 8. Philosophers have come to view inductive reasoning as raising two worries, the classic "problem of induction" posed by Hume and the so-called "new riddle of induction" posed by Goodman. What precisely are these two problems? How, if at all, is each of them germane to doing science and to giving a philosophic account of what science accomplishes? Hume's problem: How can the principle of induction (that the unobserved/future will be like the observed/past) be justified? Goodman's problem: By inductive reasoning we can conclude both that all emeralds are green and that all emeralds are grue, which is a contradiction. How can we explain why inductive is valid in the green case, but not the grue? Generalizations in science are inductive. Laws are said to hold at all times in all places. But if we have no logical reason for certainty that the future/unobserved will be like the past/observed, our generalizations are not founded on certainty and may be suspect. How many observations are needed to justify inductive inference? Theories are tentative statements which are rigorously tested. The results of an inductive inferences are falsifiable. So if they are tested and not falsified they become better justified. The more falsifiable a theory is, the better of a theory it is. If it's falsified, we learn and revise. If not, we have a stronger (more predictive) law. No general hypothesis of the form "All As are Bs" can be conclusively confirmed because it is about an indefinite number of As and experience can provide evidence only about a finite number of observations. Hypotheses can, however, be falsified. How do people decide among multiple hypotheses that are compatible with all the evidence? All observed swans are white doesn't mean there aren't unobserved black swans (there are). All peaches have pits. Goodman: Green emeralds are positive instances (provide confirmation) of both the green and grue hypotheses. How do we explain that they are not positive instances of grue? Grue is an artificial gerrymandered term which is not entrenched nor projectable. But why? We might choose between multiple hypotheses on other grounds such as simplicity and coherence. What grounds can observational data give us for accepting hypotheses whose content logically transcends the observational data? Hypotheses are confirmed by evidence. Goodman's grue. Evidence cannot discriminate between green and grue hypotheses. No body of observations can prove inductive hypotheses because they make predictions that go beyond the evidence that can be accumulated. Even though every rave observed so far has been black, we can conceive of one which is not (much like all swans are white). We cannot expect deductive certainty from inductive logic. Then, should the scientist accept universal generalizations given this fallibility? Scientists should accept them on non-observation grounds. Goodman argues that for any empirical hypothesis, it is possible to construe an alternative hypothesis that is equally well supported by the evidence to date, so that it is not clear which hypothesis is confirmed. Hume's problem of induction. Inductive inferences are not rationally justified, but are instead the result of custom or habit. The course of nature may change. Reichenbach -- if there are regularities, the inductive method will eventually find them. Induction concerns ampliative inferences whose conclusions are not validly entailed by the premises. Scientific laws are fallible because they make claims that go beyond the data and hold at all times. Problem 1: Why do we say some inductive inferences are good ones? (The sun will rise tomorrow.) The past places no logical constraints on the future, so why do we believe inductive inferences? One reason (Reichenbach) is that the results of induction are justified on other pragmatic grounds. Popper dismisses the problem by relying on falsification, not induction. Strawson says it is just a brute epistemological fact (with no explanation) that (some) inductive inferences are rational. Problem 2: How do we differential good and bad inductions (green, grue) when both have the same syntactic form? (Hajek and Hall in Black Guide) Are there degrees of confirmation, such that we should express confirmation in terms of probabilities? Observational evidence cannot justify deductive inference to truth. Russell posits an inductive principle. Is nature uniform? Goodman: any set of observations yields multiple generalizations which the observations cannot distinguish between. Answers to the grue riddle include projectible, entrenchment, simplicity. Russell: Is there any reason for believing in the uniformity of nature? The business of science is to find uniformities such as the laws of gravitation which seem to have no exceptions. Will future futures resemble past futures? When two things have been found to be often associated and no instance of one without the other is known, does the occurrence of one in a fresh instance give good grounds for expecting the other? We can never have certainty but probability. We can never be sure we have discovered an exceptionless law. All knowledge which based on experience tells us about that which is not experienced is based on the inductive inference which experience cannot confirm. (Russell) Achinson on grue: Possible solutions include avoiding temporal properties, avoiding naturally disjunctive properties, entrenchment. Specific generalizations based on the inductive inference are justified when they increase probability. See: Black Comp #28,p196+,108,54+, Rosenberg p112+, Rout #16&20, Black Guide #8, Epist p391,201, epist notes http://marr.bsee.swin.edu.au/~dtl/het704/lecture3/logfals/node5.html ========== 9. "Reductionism" is a pejorative term often applied by self-styled "holists" and "anti-reductionists" to various schools of scientific thought; yet, the "reduction" of cellular biology to chemistry, or chemistry to physics, is at the same time held up as a triumph of modern science. Describe varieties of reductionism, and evaluate some of the main arguments for and against reductionism. varieties of reduction: ontological reduction - everything that exists is made from a small number of basic substances methodological reductionism - explanations ought to be reduced to the simplest entities theoretical - older theories are not replaced by new ones but refined scientific - all phenomena can be reduced to sci explanations linguistic - everything can be described in a limited language greedy - try to explain too much with too little See: Black Comp #59&77&50, Rosenberg p79+, Black Comp Phil p 312, Meta red&unity, Dennett p80, Carnap, Rout #22 http://www.marxists.org/reference/subject/philosophy/works/at/popper.htm http://www.geog.uu.nl/fg/philosophy/abstrmk.htm http://en.wikipedia.org/wiki/Scientific_reductionism ========== 10. Duhem provides a classic statement of a widely held thesis of holism in the philosophy of science: "hypotheses shall be chosen in such a manner that from them taken as a whole mathematical deduction may draw consequences representing with a sufficient degree of approximation the totality of experimental laws." What is to be said in favor of this thesis? What is to be said against it? Why is it important to the philosophy of science? Hypotheses are chosen to be a minimal set of propositions from which the entire system of laws can be derived. Hypotheses unify laws. It's not clear that choosing hypotheses in this way leads one to hypotheses which are true in addition to being useful. See: Duhem p220+,19+, Black Comp #77, Carnap ========== 11. "Experimental evidence can at most show that a theory holds to a certain level of approximation. But any number of disparate theories can conform to all experimental evidence within any given level of approximation. Therefore, experimental evidence alone can never even justify the adoption of any one theory from the myriad of comparably accurate alternatives to it, much less establish its truth." Of what significance is this contention to the philosophy of science? Is it correct? This is, roughly, the thesis of underdetermination of theory by evidence. Agreement in the observable need not require agreement in the unobservable. It does seem that observation alone cannot also determine between theories. Curve-fitting approximation. Other considerations include simplicity, unity, ability to predict new laws, etc. Adopt for practical purposes, not truth. Underdeterminsim threatens realism. Any theory which posits unobservable phenomena has infinitely many empirically equivalent theories. If correct (which seems plausible although it doesn't much seem to happen in practice), this says that to choose between theories requires more than experimental/empirical/observational data. Why do we abandon older theories when we do (Ptolemaic in favor of Copernican)? Judgment, pragmatic factors, simplicity, coherence, unity, etc. So more than empirical plays a role. But still, might the application of these non-empirical factors still underdetermine theory choice? For instrumentalists and other anti-realists, none of this is of any concern. Theories that are empirically equivalent are equally instrumentally useful. Duehem's argument, in brief, is that at least in sciences like physics, where experiment is dense with sophisticated instrumentation whose employment itself requires theoretical interpretation, hypotheses are not tested in isolation but only as part of whole bodies of theory. It follows that when there is a conflict between theory and evidence, the fit can be restored in a multiplicity of different ways. No statement is immune to revision because of a presumed status as a definition or thanks to some other a priori warrant, and most any statement can be retained on pain of suitable adjustments elsewhere in the total body of theory. Hence, theory choice is underdetermined by evidence. Available observational evidence may not decide between rival theories. How do we decide which theory to adopt? We may look to other factors. This is weak underdetermination of theories. Strong underdetermination says that any scientific theory has an incompatible rival theory to which it is empirically equivalent. If true, this is a blow to realism, but not instrumentalism. We have preference for simpler theories. Given a theory, one can always construct an empirically equivalent rival. A scientist's acceptance of a theory involves using it as the basis for developing theories in other areas or aiming to develop it into a still better theory. Acceptance involves a commitment, not a belief. Blackwell Companion to Philosophy, p 297+ (next several paragraphs) Underdetermination of theory by observational data (UTD) based on the Duhem-Quine thesis: A scientific theory does not normally imply predictions on its own, but only in conjunction with auxiliary hypotheses. So when a prediction is falsified by observation, this may refute the hypotheses rather than the theory. Therefore any theoretical claim can be consistently retained in the face of contrary evidence by making adjustments elsewhere in the system of beliefs. Underdetermination based on Poincare and Mach: Imagine a theory that is the complete truth about physical reality and that it implies certain observational facts. We can construct a theory which postulates more complicated unobservable mechanisms but makes the same observational predictions. The argument from underdetermination asserts that, given any theory about unobservables that fits the observable facts, there will be other incompatible theories that fit the same facts. And so, the argument concludes, we are never in a position to know that any one of these theories is the truth. Duhem-Quine thesis -- any particular scientific theory can always be defended in the face of contrary observations by adjusting auxiliary hypotheses. For example, when the Newtonian theory of gravitation was threatened by observations of anomalous movements by the planet Mercury, it could always be defended by postulating a hitherto unobserved planet, say, or an inhomogeneous mass distribution in the Sun. Another argument for underdetermination starts with the same given theory. ... We can always postulate some unnecessarily complicated unobservable mechanism which nevertheless yields a new theory with precisely the same observational consequences as the original one. Is realism about unobservables untenable? There is nothing in the arguments for alternative underdetermined theories to show that these alternatives will always be equally well-supported by the data. They will all be consistent with the data, but one may be vastly more plausible than the others. Quine: But the total field is so undetermined by its boundary conditions, experience, that there is much latitude of choice as to what statements to re-evaluate in the light of any single contrary experience. No particular experiences are linked with any particular statements in the interior of the field, except indirectly through considerations of equilibrium affecting the field as a whole.... The over-all algebra of rational and irrational numbers is underdetermined by the algebra of rational numbers, but is smoother and more convenient; and it includes the algebra of rational numbers as a jagged or gerrymandered part. Total science, mathematical and natural and human, is similarly but more extremely underdetermined by experience. The edge of the system must be kept squared with experience; the rest, with all its elaborate myths or fictions, has as its objective the simplicity of laws. See: Black Comp #76&56&52, Rosenberg p129+, Black Comp Phil p297+, Rout #23&26&p348, Duhem p170+,216+, Kuhn p147+ http://www.drury.edu/ess/philsci/KleeCh4.html ========== 12. "Because every measurement is a physical process, physics cannot help but contain within its scope its own theory of measurement. This, more than anything else, has set physics off from other sciences, historically as well as logically." What are the ramifications of this claim for the philosophy of science? Do these ramifications, or any other considerations, provide grounds for rejecting it? Physics, unlike math, requires verification of the theory as a whole. See: Duhem p182+,187+,200,258,265+, Rout #22?, Black Comp #40?, Carnap?