3Empiricismem·pir·i·cism n.1. The view that experience, especially of the senses, is the only source of knowledge.John Locke (1632–1704)Bishop George Berkeley (1685–1753)David Hume (1711–1776)
4Problems with Empiricism A central tenet of Science is that all evidence comes via testable, experimental or empirical means and that scientific methods are an interplay between empirical evidence and testable conjectures. In this (somewhat innocuous use of the term) empirical = experimentalIn a more general vein, however, empiricism is a belief that all knowledge must arise from sense perception (no innate ideas). In this form empiricism is a description of how we know anything. But here is the “rub” – if knowledge comes only via sense perception then how do we “disentangle” ourselves from what we claim to know?
5The British Empiricists John Locke: No innate ideas – our minds are blank slates (“tabula rasa”) problem: how does our mind order and connect these sensations? How do we in science perceive and extend ideas?Bishop Berkeley: the world exists only through our perception of it! This leads to idealism which asserts that only our ideas of things are real – not the things themselvesDavid Hume: All that we know of the world comes from perception and knowledge claims cannot be logically justified – they arise from “habits of the mind” problem: Is scientific knowledge nothing more than a collection of “habits of mind”? Don’t “many minds” come to shared conclusions – via empirical methods – that allows science to transcend this?
6Why is the “Problem of Induction” a “problem”? Hume’s “problem of induction” seems to be impossible to get around - to paraphrase Popper, Russell and many others it seems to put science on an irrational footingDoesn’t the success of science argue that there is something palpably different about the nature of scientific knowledgeWhat, for example, do both Popper and Scheffler see as the “risk” facing science?
7Scientific Objectivity Israel SchefflerSees the very nature of science – its reliability and authority - at stake"The claim of science to represent a reliable body of knowledge rests four-square on the assumption of objectivity, on the assertion that scientists are not influenced by their prejudices or are at least protected from them by the methodology of their discipline."William Broad and Nicholas Wade, Betrayers of the Truth (1985)
8A FUNDAMENTAL FEATURE of science is its ideal of objectivity, an ideal that subjects all scientific statements to the test ofindependent and impartial criteria, recognizing no authority of personsin the realm of cognition. (pg1)Since reason is, moreover, a moral as well as an intellectual notion,we have thereby been given also anew and enlarged vision of the moral standpoint … science has certainly providedus with new and critically important knowledge of man's surroundingsand capacities, such enlightenment far from exhausts itshuman significance. A major aspect of such significance has beenthe moral import of science: its dynamic articulation of the impulseto responsible belief, and its suggestion of the hope of an increased rationality and responsibility in all realms of conduct and thought.(pg 4)
9Recent attacks against this standard view have been launched from various directions. They have varied also in scope and precision, and their larger strategic import has not always been evident, even to the combatants themselves. Yet, taken together, these attacks add up, in my opinion, to a massive threat to the very possibility of objective science. Uncoordinated as they are, they have already subtly altered the balance of philosophical forces, exposing to danger the strongest positions of the objectivist viewpoint. (pg 12)The breakdown of observational community and of the communityof meaning, and the consequent rejection of cumulativenessseem to remove all sense from the notion of a rational progression ofscientific viewpoints from age to age. (pg 17)
10Bottom Line for Scheffler But now see how far we have come from the standard view. Independentand public controls are no more, communication has failed,the common universe of things is a delusion, reality itself is madeby the scientist rather than discovered by him. In place of a communityof rational men following objective procedures in the pursuitof truth, we have a set of isolated monads, within each of whichbelief forms without systematic constraints.I cannot, myself, believe that this bleak picture, representing anextravagant idealism, is true. (pg 19)Bottom Line for SchefflerFor science to “be science” it must be rooted in a realist view of the world thatentails objective, value free knowledge claims. The “ideal of objectivity” is alimit point that coordinated scientific claims tend towards. While individualscientists may fall short of this the body of their cumulative work tends to this.Schleffler does not require certainty but he does claim a strong form of objectivitythat will resonate with Popper’s idea of Third World Knowledge.
11Sir Karl PopperTackles the problem of induction – claims to have solved it'Hume's philosophy ... represents the bankruptcy of eighteenth-centuryreasonableness' and, 'It is therefore important to discoverwhether there is any answer to Hume within a philosophy thatis wholly or mainly empirical. If not, there is no intellectual differencebetween sanity and insanity. The lunatic who believes that he is apoached egg is to be condemned solely on the ground that heis in a minority ‘Sir Bertrand Russell, A History of Western Philosophy (1946)The growth of unreason throughout the nineteenth century and what has passed of the twentieth is a natural sequel to Hume's destruction of empiricism.Bertrand Russell
12Why is this chapter titled Conjectural Knowledge? OF course, I may be mistaken; but I think that I have solved a major philosophical problem: the problem of induction. (I must have reached the solution in 1927 or thereabouts.1) This solution has been extremely fruitful, and it has enabled me to solve a good number of other philosophical problems.(pg 1)Popper agrees with Hume – you cannot, by logical means of argument,prove the Truth of a scientific claim … BUTYou can disprove (by logical means) a scientific truth claimThis has become a popular “definition” of what constitutes a scientific theory:A theory is scientific if it is potentially open to being disproved
13How to Decide Among Theories We have seen that our negative reply to L1 means that all our theories remain guesses, conjectures, hypotheses. Once we have fully accepted this purely logical result, the question arises whether there can be purely rational arguments, including empirical arguments, for preferring some conjectures or hypotheses to others.There may be various ways of looking at this question. I shall distinguish the point of view of the theoretician—the seeker for truth, and especially for true explanatory theories—from that of the practical man of action; that is, I will distinguish between theoretical preference and pragmatic preference. (pg 13)We search for truth in theories by steadfastly “chipping away” at the falsifiable bits
14Wait a minute! What IS a Scientific Theory Anyway? A scientific theory is…A collection of logically consistent statements that provide explanation of one or more observable phenomenaMakes (falsifiable) predictionsHas a deductive structure – by using a formal system of logic you can deduce outcomes by applying constructs of a theory
15Example … Theory of Stellar Structure Our modern understanding of how stars workEnergy production via fusion and other meansBasic laws of physics lead to mathematical equations or conditions:Hydrostatic equilibriumConservation of MassConservation of EnergyEnergy transportMakes testable predictions about how stars evolve!
16Doesn’t this prove the theory of stellar structure? How would Popper address thisPopper would likely conclude:This is a good scientific theory in that it makes genuine, potentially falsifiable predictions, which it has – for the most – part passedIt is not true – it must remain conjectural until it is proven falseJust because it has passed many tests in the past does NOT make it a “better theory” (see pgs 18-20)On the other hand, among the theories actually proposed there maybe more than one which is not refuted at a time t, so that wemay not know which of these we ought to prefer. But if at atime t a plurality of theories continues to compete in this way,the theoretician will try to discover how crucial experiments canbe designed between them; that is, experiments which couldfalsify and thus eliminate some of the competing theories. (pg 15)
17Pragmatic Preferences… In other words, there is no 'absolute reliance'; but since wehave to choose, it will be 'rational' to choose the best-testedtheory. This will be 'rational' in the most obvious sense of theword known to me: the best-tested theory is the one which, inthe light of our critical discussion, appears to be the best so far,and I do not know of anything more 'rational' than a well conductedcritical discussion.Of course, in choosing the best-tested theory as a basis foraction, we 'rely' on it, in some sense of the word. It may thereforeeven be described as the most 'reliable' theory available, insome sense of this term. Yet this does not say that it is 'reliable'.It is not 'reliable' at least in the sense that we shall always dowell, even in practical action, to foresee the possibility thatsomething may go wrong with our expectations. (pg 20)
18The Problem of Demarcation How do you decide between scientific and other kinds of theories?Falsifiability is the “acid test” - to be a scientific theory, a theory must contains the “seeds of its own destruction!”Is Intelligent Design a Scientific Theory
19Popper’s “Worlds of Knowledge” At the end of the day Popper is, among other things, questing after a form of scientific objectivity not unlike that of SchefflerPopper introduces 3 “Worlds” of knowledge:WORLD 1: the physical worldWORLD 2: the world thought and experienceWORLD 3: the world of objective thought“…what I call 'the third world' has admittedly much incommon with Plato's theory of Forms or Ideas…” (Objective Knowledge; pg 106)
20Let me repeat one of my standard arguments for the (more or less) independent existence of the third world.I consider two thought experiments:Experiment (i). All our machines and tools are destroyed, and all our subjective learning, including our subjective knowledge of machines and tools, and how to use them. But libraries and our capacity to learn from them survive. Clearly, after much suffering, our world may get going again.Experiment (2). As before, machines and tools are destroyed,and our subjective learning, including our subjective knowledgeof machines arid tools, and how to use them. But this time, alllibraries are destroyed also, so that our capacity to learn from booksbecomes useless.
21WORLD 3The third chapter of OK is titled “Epistemology Without A Knowing Subject”In upholding an objective third world I hope to provoke thosewhom I call 'belief philosophers': those who, like Descartes, Locke,Berkeley, Hume, Kant, or Russell, are interested in our subjectivebeliefs, and their basis or origin. Against these belief philosophersI urge that our problem is to find better and boldertheories; and that critical preference counts, but not belief.I wish to confess, however, at the very beginning, that I ama realist: I suggest, somewhat like a naive realist, that there arephysical worlds and a world of states of consciousness, and thatthese two interact. And I believe that there is a third world, ina sense which I shall explain more fully. (OK, pg 107)
22My first thesis is this. Traditional epistemology has studied knowledge or thought in a subjective sense—in the sense of theordinary usage of the words 'I know' or 'I am thinking'. This,I assert, has led students of epistemology into irrelevances: whileintending to study scientific knowledge, they studied in factsomething which is of no relevance to scientific knowledge. Forscientific knowledge simply is not knowledge in the sense of theordinary usage of the words 'I know'. While knowledge in thesense of 'I know' belongs to what I call the 'second world',the world of subjects, scientific knowledge belongs to the thirdworld, to the world of objective theories, objective problems,and objective arguments.Thus my first thesis is that the traditional epistemology, ofLocke, Berkeley, Hume, and even of Russell, is irrelevant, in apretty strict sense of the word. It is a corollary of this thesis thata large part of contemporary epistemology is irrelevant also.This includes modern epistemic logic, if we assume that it aimsat a theory of scientific knowledge. However, any epistemic logiciancan easily make himself completely immune from rny criticism,simply by making clear that he does not aim at contributing tothe theory of scientific knowledge.
23My first thesis involves the existence of two different senses of knowledge or of thought: (i) knowledge or thought in the subjectivesense, consisting of a state of mind or of consciousness or a dispositionto behave or to react, and (2) knowledge or thought in an objective sense,consisting of problems, theories, and arguments as such. Knowledge in thisobjective sense is totally independent of anybody's claim to know; it is alsoindependent of anybody's belief, or disposition to assent; or to assert, or to act.Knowledge in the objective sense is knowledge without a knower:it is knowledge without a knowing subject (pg )In this we see Popper and Scheffler converge to a common idea of “value-free, pure objective knowledge”
24Some parting thoughts on Popper Popper rightly (I think) asserts that we do not “have observations - we MAKE observations” – in doing science our observations are theory drivenPopper (as was Sheffler) was deeply suspicious of subjectivismIt is the theory that decides what we can observe. -- Albert EinsteinThe subjective approach has made much headway in scienceSince about First it took over quantum mechanics. Here it became so powerful that its opponents were regarded as nitwits who shouldrightfully be silenced. (OK, pg 141)
25Some Critical Scientific Experiments that challenge Realist Philosophies Naïve Realist:I call’emas they are!Critical Realist:I call’em asI see’mAnti-Realist:They ain’t nothintil I call’em!
26"The temper of Realism is to de-antropomorphize; to order man and mind to their proper place among the world of finite things; on the one hand, to divest physical things of the coloring which they have received from the vanity or arrogance of the mind; on the other, to assign them along with minds their due measure of self-existence." -- Samuel Alexander"The most acquisitive person is so busy re-investing that he never learns to cash in. 'Realistic people' who pursue 'practical aims' are rarely as realistic or practical, in the long run of life as the dreamers who pursue their dreams." -- Hans Selye
27Physics and Realism – Worlds in Collision! Mathematization of the worldEmergence of powerful “machine-metaphor”Discoveries in Physics challenge realist interpretation1887 HertzPhotoelectric EffectBirth ofQuantum Theory18731800Math explosion!19051687Calculus further articulated1859Differential Equations1900Planck - Quantization
28Crucial Events1887 Heinrich Hertz confirms key prediction of Maxwell’s Electromagnetic Theory and, in so doing discovers the Photoelectric Effect1900 Max Planck “discovers” quantization1905 Einstein’s “Annus Mirabilis” – radically changes our notions of space and time and introduces concept of the quantum or particle of light (= photon)De Broglie - The wave-particle duality is unleashed!Bohr-Einstein debates – quantum “reality” is unlike naïve realityThe EPR effect and Bell’s Theorem
29Next ClassDo Kuhn, Polanyi and Maxwell offer us a different way to look at science?Can science still be both reliable and “objective”?