Scientific Realism

Scientific Realism #

Scientific Realism: Science aims to give a literally true understanding of the world #

• science ⇒ discoveries, not inventions
• acceptance of theory = belief that it is true
• postulated entities exist, even if they cannot be observed directly (quarks…)

Scientific Anti-Realism #

Different Types: #

• Instrumentalism: to propose a theory is not to say it is correct, but that it is useful
• Constructive Empiricism: to propose a theory is to say it is empirically adequate
  • ↳ true about all observable things

distinction between realism and anti-realism

Observable vs Unobservable #

→ anti-realism/empiricism relies on this distinction

Definition of “observable” (Van Fraassen): can be seen with an unaided act of perception

• ↳ does not rely on external tools like telescopes

Grover Maxwell’s Objection #

• “unaided act of perception” is a very vague term/arbitrary
  • light waves can be seen as an external tool for observation
  • Van Fraassen’s response: arbitrary distinctions don’t mean they are not useful — e.g. color names are vague, but useful
• “observable” is defined as ‘can be observed’ — but what exactly can or cannot be observed?
  • Van Fraassen: again, arbitrary distinctions can be useful.

Pessimistic Meta-Induction #

In the past, all theories have been proven false. Therefore, it is likely that current theories will be proven false in the future.

• ↳ implication: science will never converge upon truth
• Implies structural realism — the idea that there exist objective, unchanging facts about the universe

The No-Miracles Argument #

• Science has produced technology and practical tools that work based on theory
  • example: phones, planes
• It is reasonable to say that these innovations are not a miracle — that the underlying theories are roughly accurate
  • i.e. “science works” because its claims are mostly true about unobservable entities
  • if true, it is not surprising that our inventions work

Issue: appeals to Inference to the Best Explanation, which is questioned by Hume’s argument

Observable Regularity #

Regular events can be explained by the existence of unobservable entities

• example: airplane flying (observable) → engine is working (unobservable)
• Why are these occurring regularly?
  • Anti-realist: regularity ends with observability
  • Realist: there is no end to regularity

Scientific vs Natural Kinds Realism #

What is the “aim” of science? #

• scientists can have many individual, differing aims (discover truth, get money, etc.)
• if an aim exists, there are conditions of “correctness” where a theory achieves an aim

(weaker) The aim of Scientific realism: A theory is correct iff it is true The aim of Scientific anti-realism: A theory is correct iff it is empirically adequate

(stronger) Scientific realism + natural kind realism: The aim of science is to determine the correct categories. A theory should be evaluated for truth AND for accuracy of natural categories used.

• “Joint-Carving”: a constraint that theories must be stated in terms of natural kinds

Scientific anti-realism + natural kind realism: A theory is correct iff it is empirically adequate and joint-carving

Truth #

All objects are correctly categorized into sets

• does not assess the validity of the categories themselves!
• If science aims for “truth”, this means science is subjective
• True AND joint-carving = better?

3 levels of scientific “correctness” #

1. true of observables
2. true of unobservables
3. joint-carving

Summary: objections to scientism #

1. epistemic relativism
2. natural kind realism
3. scientific anti-realism

Rebuttal by IBE #

if IBE, then natural kinds = simple, elegant, unifying kinds

van Fraassen’s Rebuttal #

IBE is a valid form of reasoning, but does not imply truth. IBE is an aesthetic preference.