REPRESENTING AND INTERVENING BY IAN HACKING CHAPTER 1: WHAT IS SCIENTIFIC REALISM? I. Introduction (21) A. Scientific realism 1. says that entities, states, and processes described by correct scientific theories really do exist 2. even when our theories are not yet correct, the realist tends to say that we are getting closer to the truth B. Anti-realism 1. just the opposite: no such things as electrons, photons, black holes, fields of force, etc. 2. these entities, states, processes are mere fictions invented in order to predict and produce events that interest us 3. no matter how successful these theories have been, we cannot say that they are true II. If you can spray them, then they are real (22) A. experiments with quarks, electrons, and positrons made Hacking a realist 1. not so much the quarks 2. but the electrons (and positrons) made him a realist B. he describes an updated version of the Millikan oil drop experiment used to detect the presence of quarks 1. in 1908 Millikan used the motion of charged oil droplets in an electric field in order to measure the charge of an electron 2. the new experiments similarly use a supercooled, superconducting, electrically charged niobium ball suspended in a magnetic field to detect the presence of a free quark with charge 1/3 e (23) C. when he asked the physicist how they change the charge on the niobium ball, he was told that they spray it with positrons or electrons D. this answer decided Hacking in favor of realism 1. not the quarks: quarks with fractional charges are a matter of controversy 2. but the positrons and electrons: if they can be sprayed, they are real (23-4) a. we understand their causes and effects b. and we can use them to find out other things 3. similarly, if he had been alive in 1908, he might have been skeptical about the reality of electrons III. What is the argument about? (24) A. Anti-realism, he recognizes, can not be so easily dismissed B. part of the problem is that many of the arguments over realism confuse realism with some other philosophical issue, such as: 1. materialism 2. the role of causes in science (hence positivist rejection of theoretical entities) 3. epistemological issues, as in the sensationalist philosophy that only what we experience is real (24) 4. semantic questions, such as what it means to say that something is "true" or "false" (25) C. discussions of realism and anti-realism may also arise in the context of specific scientific debates 1. Copernican astronomy: useful or real? 2. more recently: quantum mechanics, esp. with regard to quantum indeterminacy 3. Freud's libido and superego 4. Durkheim's social forces and processes D. can one be a realist about the entities postulated by one science but not by another? E. Anti-philosophical positions 1. cynicism: although it may have made sense at one time to worry whether atoms are real, today it is silly 2. philosophical anti-philosophy: the whole realist/antirealist issue is founded on a mistaken conception of knowledge as "representing" reality IV. Movements, not doctrines (26) A. realism and anti-realism are more like movements in philosophy of science than a specific set of doctrines 1. compares them to movements in literature and art 2. this is not to say that movements do not have doctrines -- or issue manifestos 3. but to say that they are defined more by a set of attitudes or motivations B. within each of these movements, there are many different doctrines or opinions V. Truth and real existence A. Two basic kinds of realism: 1. about theories 2. about entities B. theories (27) 1. the question about theories is whether they are the sorts of things that can be true or false 2. to believe in the truth of a theory is not necessarily to believe in the reality of the entities that it postulates a. using symbolic logic, we can rewrite a scientific theory in such a way as to replace every mention of the entity with a variable b. the resulting statement may still be true in that it agrees with the facts C. entities 1. one can be a realist about entities without being a realist about theories 2. example: a theologian may be a realist about God without believing that we can have any true theories about God -- other than negative claims such as not finite, etc. 3. similarly, one can be a realist about electrons without believing that any of our present theories of electrons are true VI. Two realisms (27) A. realism about entities 1. says that a good many scientific entities exist 2. anti-realism denies this a. says either that they are mere fictions, constructions, instruments b. or that we have no reason to believe that they are not just fictions 1.) they may exist 2.) but we do not need to believe that they exist in order to do science B. Realism about theories 1. theories are true or false independently of our knowledge of them a. science aims at the truth b. "truth is how the world is" 2. anti-realism: a. that all we may have is something like sufficient warrant to accept or work on a theory (28) b. but can never have a good reason to believe a theory VII. Subdivisions (28) A. admits that he has just run together: 1. metaphysical claims about reality 2. epistemological claims about what we can know B. that is, Hacking's realism says that: 1. entities exist and are not mere intellectual tools 2. we have warranted beliefs in such entities C. Newton-Smith separates realism into 3 distinct ingredients: 1. ontological: a. scientific theories are true or false b. what they are -- true or false -- they are in virtue of the way the world is 2. causal: if a theory is true, the theoretical terms denote entities that are causally responsible for the observable phenomena 3. epistemological: we can have warranted belief in theories or entities D. Anti-realist positions 1. Instrumentalism denies # 1: a. theories are not to be taken literally b. they are not true or false c. they are only useful tools for making predictions 2. van Fraassen's constructive empiricism: denies # 3 a. theories are to be taken literally: they must be either true or false (29) b. but we never have any warrant to believe any theories about the unobservable E. Realist positions (29) 1. realism about theories: combines 1 and 3 2. realism about entities a. close to a combination of 2 and 3 b. differs with respect to 2: we can believe in entities without believing in any particular theories about them F. Nancy Cartwright 1. believes that we can never have true, explanatory, fundamental theories about entities: only phenomenological laws can be true 2. e.g. Crooke's radiometer 3. nevertheless, we can know about causally effective theoretical entities VIII. Metaphysics and the special sciences (29) A. must also distinguish realism in general from realism in particular B. that is, one could be a realist in general while doubting the reality of some particular entity, say, photons 1. whether photons are real is a question for optics, not for philosophy (30) 2. finds it quite common for a discipline to start off as anti-realist about some entity or its theories and then to become gradually more realist 3. the issue of realism about some particular theory or entity is settled by further research (31) C. realism in general 1. not settled by further research 2. more a philosophical position D. although these two positions are logically distinct, in the actual history of science and philosophy they have been combined IX. Representation and intervention (31) A. 2 aims of science: 1. theory a. to say how the world is b. that is, to provide a representation of the world 2. experiment a. along with subsequent technology, to change the world b. intervening B. the two are linked: 1. we represent in order to intervene 2. our interventions are guided by representations C. representation and realism 1. most debates about realism concern representation 2. Hacking suspects that at this level there can be no decisive arguments 3. but with respect to intervening, anti-realism is less persuasive