Summary: Chapter 15 in What Is This Thing Called Science? / Alan Chalmers

What Is This Thing Called Science? / Alan Chalmers

Chapter 15:Realism and anti- realism

-          Realism = science describes not just the observable world but also the world that lies behind the appearances

-          Doubts abut realism: extent to which claims about the unobservable world must be hypothetical to the extent that they do transcend what can be firmly established on the basis of observation

Global anti-realism

-          We are trapped within language and cannot break out of it to describe reality directly in a way that is independent of our theories

-          (Realist) correspondence theory of truth = a sentence is truth if and only if it corresponds to the facts

-          Liar paradox: e.g. I never tell the truth

-          Tarski: avoid paradoxes by distinguishing the object language (is being talked about) from the meta-language (in which the talking is done)

-           A theory is true if the world is as the theory says it is and false otherwise

-          Should scientific theories be taken as candidates for truth or as making claims about the observable world only? Neither side supports global anti-realism

Anti-realism

-          Instrumentalists: theories are just useful instruments to predict results

-          Van Fraassen is not an instrumentalist for theories can be true or false, but the merit is judged in terms of its generality and simplicity and the extent to which it leads to new observations à constructive empiricism

-          Motivation of anti-realism = desire to restrict science to those claims that can be justified by scientific means. Evaluate theories solely in terms of their ability to order and predict observable phenomena

-          Theories can be discarded when they have outlived their usefulness, and the experimental and observational discoveries to which they have led retained

Objections and anti-realists response

-          Distinction between knowledge at the observational level (securely established) and is best seen as an heuristic aid à problem: theory dependence and fallibility of observation and experiment

-          Theories that are predictively successful have to be more or less true and not just instruments à response anti-realists: fact that a theory is productive need be no indication that it is true (historical proof)

-          Anti-realists insist that theories must be general and unified – embrace a wide range of phenomena

-          The unobservable has no place in science or should be treated merely as useful fiction (e.g. atomic theory) à response: only part of science that is subject to confirmation by observation and experiment should be treated as candidates for truth and falsity, but as science progresses and better instruments and experimental techniques are devised à range of claims that can be subject to confirmation is extended

Scientific realism

-          Science aims at true statements about what there is in the world and how it behaves at all levels. Science has made progress to this aim

-          Impossible to know that current theories are true, but they are truer than earlier theories

-          Hacking: pay attention to what can be practically manipulated in science. Entities in science can be shown to be real once they can be manipulated in a controlled way and used to bring about effects in something else

Conjectural realism (Karl Popper)

-          Theories of the past have been falsified and replaced by superior theories

-           Problem: weakness of its claims. Science aims to achieve truth and there are ways to recognize how it falls short of this aim (there is no truth)

Structural realism

-          Middle ground realism and anti-realism: realist in that it attempt to characterizes the structure of reality: more and more capable. Representations are replaced over time

Idealization

-          Duhem: theories cannot be taken as literal descriptions of reality because theoretical descriptions are idealized in a way that the world is not

-          Theoretical and observational knowledge

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Summary: Chapter 9 in What Is This Thing Called Science? / Alan Chalmers

What Is This Thing Called Science? / Alan Chalmers

Chapter 9: Theories as structures: Research programs

-          Commonalities Kuhn and Popper:

o   Reject positivism and inductivism

o   Priority to theory over observation

-          Lakatos set out to modify falsificationism to rid it of its difficulties and does so by drawing on some of Kuhn’s ideas.

-          Fundamental principles = hard core of a research program à basis from which the program is to develop, general hypotheses

-          Any inadequacy in the match between an articulated program and observation is to be attributed to the supplementary assumptions rather than the hard core

-          Protective belt = sum of additional hypotheses supplementing the hard core à its role is to protect the hard core from falsification

-          Assumptions in the protective belt are to be modified in an attempt to improve the research program (the match of its predictions and the actual results of observation and experiment)

-          Negative heuristic = what the scientist should not do

-          Positive heuristic = what the scientist should do, suggestions on how to sophisticate the protective belt

-          Early work in a research program takes place in spite of apparent falsifications. In this early stage confirmations rather than falsifications are of paramount significance

-          Indication of the merit of a program > extent to which it leads to novel predictions that are confirmed

-          Progressive research program = retains its coherence and at least intermittently leads to novel predictions that are confirmed

-          Degenerating program = loses its coherence and/or fails to lead to confirmed new predictions

-          Scientific revolution for Lakatos: the replacement of a degenerating program by a progressive one

Methodology within a program and the comparison of programs

-          No ad hoc modifications

-          Modifications or additions to the protective belt must be independently testable and open up opportunity for new tests

-          Impossible to do research that departs from the hard core

-          Novel predictions: one program is superior to another insofar as it is a more successful predictor of novel phenomena

-          Support Quine/Durkheim thesis

-          Not irrational to remain working on a degenerating program if there are possible ways to bring it to life again

-          Appraisal of research programs can only be done with historical hindsight

Problems with Lakatos’s methodology

-          Hard core of a program is rendered unfalsifiable by the methodological decisions of its protagonists à lack of evidence of those rational decisions and yet they are the locus of distinction between his position and that of Kuhn

-          Methodology can only make judgments whether a program is scientific or not with the benefit of historical hindsight àno position to diagnose a contemporary program

-          Support with history of science but only that of physics, assumed that other fields share the characteristics of physics à problematic because especially in the social sciences, knowledge produced itself is a component of the system that is studied, so a change in theory can bring about a change in the system

Back to:  What Is This Thing Called Science? / Alan Chalmers

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Summary: Chapter 8 in What Is This Thing Called Science? / Alan Chalmers

What Is This Thing Called Science? / Alan Chalmers

Chapter 8: Theories as structures: Kuhn’s paradigms

-          In his "Structure of Scientific Revolutions" Kuhn describes the progress of science

o   Pre-science à normal science à crisis à revolution à new normal science à new crisis

-          Existence of a paradigm capable of supporting a normal science tradition is the characteristic that distinguishes science from non-science

-          Mature science is governed by a single paradigm

-          Normal science as puzzle-solving activity governed y the rules of a paradigm

-          Lack of agreement over fundamental distinguishes mature science from disorganized immature pre-science

-          Mere existence of unresolved puzzles does not constitute a crisis

-          When anomalies come to be seen as posing serious problems for a paradigm à crisis which is deepened with the appearance of an incompatible rival paradigm. Rival paradigms are incommensurable

-          Scientific revolution: abandonment of one paradigm and the adoption by a new one by the relevant scientific community as a whole

-          Importance attached to the role played by the sociological characteristics of scientific communities

-          Function of revolutions: a means of breaking out of one paradigm into a better one

-          Progress through revolutions: alternative to cumulative progress

-          A discipline in which fundamentals are constantly brought into question (critical rationalism) is unlikely to make significant progress simply because principles do not remain unchallenged long enough for esoteric work to be done

Kuhn’s ambivalence on progress through revolutions

-          Relativist position: the question of whether a paradigm is better or not than the one it challenges does not have a definitive neutral answer, but depends on the values of those who make the judgment

-          Kuhn rejects the relativist position: later theories are better than earlier ones for solving puzzles in the different environments to which they are applied à convinced believer in scientific progress

-          Two incompatible strands: the relativist position and the alternative (how can a paradigm be said to constitute progress over the one it replaces?)

Objective knowledge

-          How can a paradigm change take place all at once, but not necessarily in an instant?

-          Distinction objective and subjective knowledge

-          Knowledge is a state of mind

-          Knowledge in the subjective sense: individual knowledge/experiences

-          Knowledge in the objective sense: distinct from the kinds of things that reside in individual minds, observation statements are publicly testable and debatable

-          Objective relationships exist between parts of the structure independently of whether individuals are aware of that relationship

-          Similar to Karl Popper’s world 3

-          A particular paradigm can be an improvement on its rival? à question about the objective relation between paradigms

-          On subjective knowledge: gestalt switches à should be removed from Kuhn’s account for it leads to the confusion and understanding of Kuhn as a relativist

Back to:  What Is This Thing Called Science? / Alan Chalmers

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Summary: Chapter 5-7 in What Is This Thing Called Science? / Alan Chalmers

What Is This Thing Called Science? / Alan Chalmers
Chapter 5-7

Chapter 5: Introducing falsification

-          Falsification is logical
-          A hypothesis must be falsifiable
-          A falsified theory must be rejected
-          Science progresses by trial and error
-          Theories should be clearly stated, precise and informative
-          Theories are never true, although they can be superior to predecessors that have been falsified
-          Science starts with problems that arise from observations

Chapter 6: Sophisticated falsification

-          Hypothesis must be more falsifiable than the one it replaces
-          Number of potential falsifiers is infinite
-          Theory is falsified if another theory:
o   Has more empirical content over old theory
o   Includes unrefuted content of old theory
o   New content is supported by empirical and observation
-          Ad hoc modifications are unacceptable as it only reduces the number of potential falsifiers
-          Modified theories that lead to new independently testable tests
-          Significant advances will be marked by
o   Confirmation (verification) of bold conjectures as such conjectures can falsify, some part, of the background knowledge
o   Falsification of cautious conjectures
-          Bold and novel are historically relative notions

Chapter 7: Limitations of falsification

-          Inconsistency: evidence/observation may be at fault rather than the theory itself à no ground to reject theory
-          Realistic scientific theory consists of:
o   Auxiliary assumptions
o   Initial conditions
-          Durkheim/Quine thesis: if the prediction is false, then it is either the theory, the auxiliary assumptions or the initial conditions that are responsible for the erroneous prediction
-          Theory can be protected from falsification by deflecting it to some other part of the web of assumptions
-          Falsification encourages bold statements
-          Need for dogmatism: do not reject theories too easily/ give into criticisms
-          What is left of falsificationism once dogmatism is allowed a key role?

Other notes

-          Knowledge = a conjecture/statements that are falsifiable and have not been falsified yet
-          To falsify is to ask the question: can I think of an event that would falsify my theory?

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Summary: Chapter 4 in What Is This Thing Called Science? / Alan Chalmers

What Is This Thing Called Science? / Alan Chalmers

Chapter 4: Deriving theories from facts

• -          Scientific knowledge is constructed by first establishing the facts and subsequently building the theory to fit them à untenable
• -          A logically valid deduction is if the premises are true, then the conclusion must be true
• -          To assert the premises as true and to deny the conclusion = contradiction
• -          An argument can be valid deduction even if it involves a false premise
• -          Truth of factual statements that constitute the premises cannot be established by appeal to logic
• Can scientific laws be derived from the facts?
• -          No it cannot if derive is interpreted as logically deduce
• -          Universal statements refer to all events of a particular kind
• -          But a number of true observations does not guarantee a true conclusion à not logical
• -          Arguments which proceed from a finite number of specific facts to a general conclusion are inductive arguments, as distinct from logical, deductive arguments
• What constitutes a good inductive argument?
• -          Not all generalizations from the observable facts are warranted
• -          Conditions that must be satisfied to justify an inductive inference from observable facts to laws:
• 1.       Large number of observations
• 2.       Repetition under a wide variety of conditions
• 3.       No accepted observation statement can conflict with the derived law
• -          Principle of induction: if a large number of A have been observed under a wide variety of conditions and if all those A without exception possess the property B then all A have the property B
• -          Condition 1: problem of arbitrariness of large number
• -          Condition 2: problem what counts as a significant variation? – draw on prior knowledge
• -          Condition 3: little knowledge would survive the demand that there can be NO exceptions
• Further problems with inductivism
• -          Unobservable knowledge cannot be established by inductive reasoning
• -          All observations are subject to some degree of error, yet many scientific laws take the form of exact mathematical formulas à how can exact laws ever be inductively justified on the basis of inexact evidence?
• -          Hume: problem of induction arises for anyone who subscribes to the view that scientific knowledge in all its aspects must be justified either by an appeal to (deductive) logic (impossible) or by deriving it from experience
• -          A general statement asserting the validity of the principle of induction is inferred from a number of instances of its successful application à inductive argument
• -          One cannot justify induction by appealing to induction
• -          The probability of the law in the light of the evidence is thus a finite number divided by infinity, which remains zero by whatever factor the finite amount of evidence is increased
• -          Initial conditions: descriptions of experimental set-ups
•  
• 1.       Laws and theories
• 2.       Initial conditions
• 3.       Predictions and explanations
• -          Observable facts are established by an unprejudiced use of the senses (no subjective opinion)

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Summary: chapter 2 in What Is This Thing Called Science? / Alan Chalmers

What Is This Thing Called Science? / Alan Chalmers

Chapter 2: Observation as practical intervention

Observation according to Chalmers is not passive à range or things are done to establish the validity of a perception

-   If validity of perceptions is doubted à take action to remove the problem (e.g. touch, taste and dissect the object of observation)

-  Action can be taken to explore the adequacy of claims put forward as observable facts, so subjective aspects of perception need not be an intractable problem for science. Observable facts objective but fallible

- An observation statement constitutes a fact worthy of forming part of the basis for science if it is such that it can be tested by the senses and withstands those tests à emphasis on tests brings out active, public character of the vindication of observation statements

Observations suitable for constituting a basis for scientific knowledge are both objective and fallible. They are objective insofar as they can be publicly tested by straightforward procedures, and they are fallible insofar as they may be undermined by new kinds of tests made possible by advances in science and technology.

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