Scientific RealismBrian Galvin Kevin Bernhardt Troy Buckner

What is scientific realism?

•Positive epistemic attitude towards the content of our best scientific theories and models

•Basically, it’s the idea that science, although not perfect, is doing a decent job of explaining the world

Observable vs. Unobservable

•Observable – things that can be perceived by our unaided senses (planets, platypuses)

•Unobservable – cannot be perceived by our unaided senses (proteins, protons, etc.)

•Scientific realism does not discriminate between the two

Varying Definitions

•Most define scientific realism in terms of the truth or approximate truth of scientific theories or certain aspects of theories

•Some define it in terms of the successful reference of theoretical terms to things in the world, both observable and unobservable

•Others define it not in terms of truth or reference, but in terms of belief in the ontology of scientific theories.

What do they have in common?•A commitment to the idea that our best

theories have a certain epistemic status•They yield knowledge of aspects of the

world, including unobservable aspects.

What is a scientific realist?

•Someone who believes that science aims to produce true descriptions of things in the world

Three Dimensions of Realist Commitment•Metaphysical – idea that the world exists

outside of our minds•Semantic – literal interpretation of

scientific claims made about the world. Any claims should be stated as fact, whether true or not.

•Epistemological – theoretical claims constitute knowledge of the world

What does scientific realism mean?•Our best scientific theories give true or

approximately true descriptions of observable and unobservable aspects of a mind-independent world

Qualifications and Variations

•What theories should realists be realist about?

•Many of our theories are likely false in the strictest sense, but they might be very close to true

Maturity of theories

•Theories suitable for realist commitment are called “mature”

•Came from a well-established field•Has been around a while•Has survived scrutiny and scientific

testing•The more mature, the greater the

commitment from realists•Realists believe that as science develops

over time, theories converge closer to truth

Three Variations of Realism

•Explanationist – reserves greatest commitment to components of a theory that are indispensible to explaining their empirical success

•Entity – causal knowledge of an unobservable entity is enough to support realism regarding it

•Structural – One should be a realist because of the physical structure of things, not because of descriptions of their nature

Considerations in Favor of Scientific Realism (and Responses)• 1. The Miracle Argument:

▫ Best theories are extremely successful.▫ Why?▫ Realist: Because they are true! If not, it must be a miracle that

they work so well.

• Rebuttal: Why do we need an explanation of success?▫ Theories = Well-adapted organisms

• What makes a particular theory successful (not just in general)?▫ Identify specific features, explanation of unobservables

• Base rate fallacy▫ If a theory is successful, we cannot claim it as true since we do

not know the base rate of true theories (could be a false positive)

Considerations in Favor of Scientific Realism (and Responses)•2. Corroboration

▫ Unobservables detected through multiple techniques.

▫ Light vs. ▫ electron microscopy

• Rebuttal: Intention of reproducing existing output.

Considerations in Favor of Scientific Realism (and Responses)•3. Selective Optimism/Skepticism

▫A. Explanationism Focus on parts of theories worthy of realist

commitment True theoretical components survive and live

in current theories Problem: Realists must provide a objective

measure to pick out crucial parts, not post-hoc.

Considerations in Favor of Scientific Realism (and Responses)

▫B. Entity Realism The more you can manipulate the unobservable

and produce predicted outcomes, the more believable a theory is.

Entity Realist: Belief of entity vs. belief of theory describing it – 2 different things. Disputed claim...

▫C. Structural Realism Epistemic view: Describes relationships between

unobservables, not their nature. Ontic view: Knowledge of unobservables’

structure. Problem: Can you know structure without

relationships?

Considerations Against Scientific Realism (and Responses)• Underdetermination of Theory by Data

▫Hypotheses (i.e. testable predictions) cannot stand alone – they require “auxiliary” assumptions.

▫Hypothesis = incorrect. Error may not exist in claim, per se

▫Problem to Realists:

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Considerations Against Scientific Realism (and Responses)... Underdetermination of Theory by Data

•Rebuttal: Realism rely on two explanations:▫A “wait and see” mentality▫Data is apt to change over time

Considerations Against Scientific Realism (and Responses)• Skepticism about Inference to the Best

Explanation▫Realist: Although many theories exist, one will have

explanatory superiority (i.e. provide the “best” explanation)

▫But will this thinking yield knowledge?▫2 problems:

A. How to judge theories in relation to being true (criteria and meaning)

B. “Best of a bad lot” argument• Rebuttal: The “best of a bad lot” may still describe

unobservables in a way to meet standards of realism....

Considerations Against Scientific Realism (and Responses)•The Pessimistic Induction

▫If most previous theories are false, so are current ones!

•Rebuttal:▫Considering only the mature theories.▫Base rate fallacy▫A few good examples should lead

antirealists to reconsider....

Considerations Against Scientific Realism (and Responses)•Skepticism about Approximate Truth

▫Abstraction and idealization seen in even our best theories.....

▫Gradually converging on truth – theories are open to improvement

▫Problem: Defining approximate truth Formally: Comparing true/false

consequences, world’s approach, type hierarchy approach

Informally: “theories build on ‘limiting cases’ from their predeccesors”

Antirealism - Realism vs. the ism’s

•Any position apposed to Realism

via one or more of the following

▫Mind is not independent of reality

▫Theories may not be interpreted literally

▫Theories may not constitute knowledge of observable and unobservable

Realism vs. the ism’s

•Empiricism

▫Doesn't like the idea that one can gain knowledge of the unobservable

▫This position believes knowledge can only be acquired through experience.

Realism vs. the ism’s

•Constructive Empiricism (Sometimes referred to as

Instrumentalism)▫Van Fraassens revision of Empiricism▫A more realistic view – not as picky▫Can believe theories that include the

unobservable only if nothing is concluded about the unobservable

▫Still kind of picky and still antirealism

Realism vs. the ism’s

•Historicism

▫Two concepts can only be understood in correctly historicized manner - from the perspectives of the paradigms in which they occur

▫Kuhn brought this ism about with “The Structure of Scientific Revolutions”

▫Antirealism due to mind not existing independent of the world

Realism vs. the ism’s

•Social Constructivism

▫States any knowledge generating process is influenced by social factors

▫SSK - sociology of scientific knowledge – studies the social aspects of how science studies the world

▫Because all knowledge is influenced by social factors, the mind is not independent of reality

Realism vs. the ism’s

•Pragmatism & Quietism

▫Does anyone really know?

▫Dialectical Paralysis – too many isim’s

▫Quietism states that nothing sensible can be said.

Wittgenstein

▫The competition between isim’s causes a problem within its self

Realism & the ism’s vs. NOA• NOA – Natural Ontological Attitude

▫A compromise of the core common realist and antirealist theories

▫NOA argues neither realism or antirealism is tenable

▫Are disputes between realism and antirealism resolvable? No because all positions come with their own rules

▫But this exercise in futility does lead to a great deal of insight of how knowledge comes about