ACADEMIEJAAR 2025-2026
PHILOSOPHY OF SCIENCE
PROF. COLIN JAKOB RITTBERG
PSYCHOLOGIE
1E BACHELOR
VUB
,Inhoudsopgave
Chapter 1 – Introduction ......................................................................................................................... 4
1 Historical overview: normative approaches and the practice turn .............................................................. 4
2 Science is great ....................................................................................................................................... 7
3 Knowledge as justified true belief (JTB account of knowledge) .................................................................... 8
4 Scientific justifications are special ........................................................................................................... 8
Chapter 2 – The demarcation problem (Ladyman; chapters 1-3) (Hacking; Introduction) .......................... 10
1 Why does demarcation matter? ............................................................................................................. 10
2 Deductive and Inductive reasoning ......................................................................................................... 12
3 Naïve vertificationism ............................................................................................................................ 13
3.1 Naïve verificationism’s answer to the demarcation problem .............................................................. 14
3.2 Is naïve verificationism convincing? ................................................................................................. 14
3.3 Does the inductive method produce knowledge? .............................................................................. 14
3.4 The problem of induction ................................................................................................................. 15
4 The demarcation problem in 1900 .......................................................................................................... 16
5 Confirmationism ................................................................................................................................... 16
5.1 Popper on Marxism and psychoanalysis ........................................................................................... 16
5.2 Good scientific theories (according to Popper).................................................................................. 17
6 Falsificationism (Popper) ....................................................................................................................... 17
7 Impact .................................................................................................................................................. 18
7.1 On truth .......................................................................................................................................... 19
Chapter 3 – Towards Historicism: the geocentrism/heliocentrism case study (Ladyman; chapter 4.4) ..... 20
1 The Ptolemaic System – Geocentrism..................................................................................................... 20
1.1 Intellectual Background ................................................................................................................... 20
1.2 Claudius Ptolemy ............................................................................................................................ 20
1.3 Circles upon circles ......................................................................................................................... 20
2 Heliocentrism ....................................................................................................................................... 22
2.1 Copernicus (1473–1543) .................................................................................................................. 22
2.2 Tycho Brahe (1546–1601) ................................................................................................................. 23
2.3 Johannes Kepler (1571–1630) ........................................................................................................... 24
2.4 Galileo Galilei (1564–1642) .............................................................................................................. 24
2.5 Relevant take-aways........................................................................................................................ 26
3 Case studies as a method (Not relevant for exam, useful for deeper understanding) ................................. 27
3.1 Methodological debate .................................................................................................................... 27
Chapter 4 – Scientific rationality in practice (Ladyman; chapter 4) .......................................................... 28
1 Thomas Samuel Kuhn (1922 – 1996) ....................................................................................................... 28
1.1 Why does Khun matter? ................................................................................................................... 28
1.2 Against “theory talk” ........................................................................................................................ 28
2 Paradigms ............................................................................................................................................ 29
2.1 Paradigms as the Constellation of Group Commitments ................................................................... 29
2.2 Paradigms as Shared Examples ....................................................................................................... 30
3 The four phases of scientific development .............................................................................................. 30
3.1 Pre-paradigmatic phase: Before there is a shared paradigm .............................................................. 31
3.2 Normal Science: Science under a dominant paradigm ...................................................................... 32
3.3 Crisis: When the paradigm begins to break down .............................................................................. 33
3.4 Revolution: Paradigm shift - a new framework replaces the old.................................................... 33
1
, 4 Incommensurability .............................................................................................................................. 34
5 The Popper-Kuhn debate ....................................................................................................................... 35
5.1 Is science cumulative and objective, or revolutionary and socially embedded? ............................ 35
6 Post-Khun: The practice-turn in the philosophy of science ....................................................................... 36
Chapter 5 – Practicing scientific rationality (Hacking; chapter 8)............................................................. 38
1 Imre Lakatos (1922-1974) ...................................................................................................................... 38
1.1 Some original sources ..................................................................................................................... 38
1.2 Content & Structure of Lakato’s lecture ............................................................................................ 40
1.3 Where to situate Lakatos on the normative/descriptive divide in the PhiSci? ...................................... 40
1.4 Scientific research programmes (SRP).............................................................................................. 41
2 Paul Feyerabend (1924-1994) ................................................................................................................ 44
2.1 Theoretical Anarchism ..................................................................................................................... 45
2.2 Anything goes .................................................................................................................................. 45
2.3 Proliferation of theory ...................................................................................................................... 46
2.4 Galileo and the church .................................................................................................................... 48
2.5 Context of discovery & Context of Justification .................................................................................. 48
Chapter 6 – Philosophy of mathematics ................................................................................................ 50
1 Genesis of the paper.............................................................................................................................. 50
1.1 From epistemic injustice to epistemic exclusion ............................................................................... 50
Practices and justified exclusion: .......................................................................................................... 50
2 The Phenomenon .................................................................................................................................. 51
2.1 Community conception of ‘cranks’................................................................................................... 51
2.2 What about it? ................................................................................................................................. 52
3 Time management is nothing new .......................................................................................................... 54
3.1 Standard Academic Publishing ........................................................................................................ 54
1.2 Time management: reviewing strategies in mathematics ................................................................... 55
4 Crank ≠ Crank: teasing apart the concept ............................................................................................... 55
4.1 Manifest and operative concepts ..................................................................................................... 55
5 Some insights ....................................................................................................................................... 56
Chapter 7 – Feminist philosophy of science ........................................................................................... 57
1 Four waves of feminism ......................................................................................................................... 57
2 Themes in feminist philosophy of science ............................................................................................... 57
2.1 The ideal of value-free science ......................................................................................................... 57
2.2 Standpoint Theory ........................................................................................................................... 58
2.3 José medina .................................................................................................................................... 58
2.4 Problems with (early) feminist in PhilSci ........................................................................................... 58
3 Helen Logino on objectivity in science .................................................................................................... 59
3.1 Strategy 1: Critiques of science Itself ................................................................................................ 59
3.2 Strategy 2: Critiques of Philosophy of Science and Rationality ........................................................... 60
3.3 Strategy 3: Critiques of the Institutional and Aocial Structures of Science .......................................... 60
3.4 Longino’s concern ........................................................................................................................... 61
3.5 Four Criteria for Objectivity (Longino) ............................................................................................... 62
3.6 Summary ........................................................................................................................................ 63
3.7 Criticism Longino’s account of Objectivity ........................................................................................ 63
Chapter 8 – Realism vs Anti-realism (Hacking; chapter 1) ....................................................................... 64
1 Metaphysics ......................................................................................................................................... 64
1.1 Realism vs. anti-realism .................................................................................................................. 64
1.2 Entity (anti-)realism and theory (anti-)realism ................................................................................... 66
2
, 1.3 Hacking: if you can intervene on it, then it’s real ................................................................................ 67
Chapter 9 – Philosophy of Mind ............................................................................................................. 69
1 Mind-Body Dualism ............................................................................................................................... 69
1.1 Descartes ....................................................................................................................................... 69
2 Behaviourism (Gilbert Ryle (1900–1976) & Rudolf Carnap (1891–1970)) .................................................... 71
3 Identity Theory ...................................................................................................................................... 72
4 Functionalism ....................................................................................................................................... 73
5 The Hard Problem (Chalmers, 1996) ....................................................................................................... 74
Chapter 10 – Philosophy of Technology ................................................................................................. 76
1 What is a technology? ............................................................................................................................ 76
1.1 Technologie as practice ................................................................................................................... 76
1.2 Technology as a system ................................................................................................................... 76
2 Technology = applied science? .............................................................................................................. 77
3 Values and Technology .......................................................................................................................... 77
4 AI and scientific explanation .................................................................................................................. 78
Voorbeeld vragen examen .................................................................................................................... 79
3
,Chapter 1 – Introduction
1 Historical overview: normative approaches and the practice turn
1 Layman’s verificationism (1900-today)
The simple idea that science works by verifying things — that we can prove or confirm whether
something is true.
For example: proving that atoms exist, that smoking causes cancer, or that climate change is real.
Two Problems:
- The problem of induction: we can only observe a limited number of cases (e.g. all swans
we’ve seen are white), but that doesn’t prove all swans are white. We can’t verify
everything.
- The historical problem: if theories are truly verified, why do we later replace them? For
instance, Newton’s physics was once seen as true, but Einstein showed it was incomplete.
➞ Layman’s verificationism is a naive belief that science can fully prove things true, while in
reality, scientific knowledge is always limited and changeable.
2 Popper’s falsificationism (1930s)
Science cannot prove a theory true — it can only test it and try to show it’s false.
A theory is scientific if it can be falsified:
- Scientists make predictions based on a theory.
- If observations go against those predictions, the theory is falsified and must be revised or
rejected.
- If no falsifying evidence appears yet, we keep the theory for now — but it’s never proven
true.
This idea helps separate science from non-science.
For example: evolution can be tested and possibly disproven (so it’s scientific), while creationism
or astrology cannot be falsified (so they are not scientific).
➞ Falsificationism means science advances by eliminating false theories, not by proving true
ones.
4
,3 Kuhn’s historicism (1960s)
Focuses on how science actually works in practice, rather than how it should work in theory.
Kuhn noticed that scientists do not behave the way Popper described — they don’t constantly try
to falsify their own theories. Instead, most scientists work within an accepted paradigm (a shared
framework of ideas and methods). Over time, new discoveries can cause a scientific revolution,
where one paradigm is replaced by another (for example, Newtonian physics → Einstein’s
relativity).
Unlike Popper, Kuhn doesn’t try to solve the demarcation problem (what counts as real science).
He doesn’t define what science is, but rather describes how it changes over time — based on
history.
➞ Kuhn’s historicism sees science as a historical and social process that evolves through
paradigm shifts, not through strict falsification or verification.
4 Lakatos’s rational reconstructions (later 1960s)
Tries to combine Popper’s and Kuhn’s ideas.
Like Kuhn: Lakatos believed philosophy of science must stay close to how science really happens
— not just abstract theory.
Like Popper: he thought it’s still important to find a demarcation criterion: a way to tell good
science from bad science.
Lakatos said we shouldn’t judge single theories but rather research programs — groups of related
theories that evolve over time. A program is scientifically strong if it leads to new discoveries and
predictions; it’s weak or degenerating if it only explains past results without progress.
➞ Lakatos’s rational reconstructions combine realism about how science works (like Kuhn) with
Popper’s goal of distinguishing progressive from non-scientific research.
5 Feyerabend’s methodological anarchism (1970s)
Rejects the idea that there is one correct scientific method.
He argued that every rule philosophers make to define what counts as real science eventually fails
when you look at history — because scientists have always broken the rules and still made
progress. That’s why he famously said: “Anything goes.”
5
, In his book Against Method, Feyerabend claimed that trying to impose strict methods or
boundaries on science limits creativity and discovery. Instead, science advances through freedom,
diversity, and even chaos, not through fixed procedures.
➞ Feyerabend’s methodological anarchism says there is no single scientific method — successful
science often ignores the rules philosophers try to create.
6 Bloor’s sociological reductionism (1970s)
Focuses on explaining scientific beliefs through social factors, not through truth or falsity.
Bloor, founder of the Strong Programme in Edinburgh, argued for the principle of symmetry: both
true and false beliefs should be explained in the same sociological way — by looking at culture,
interests, power, and context.
He didn’t try to separate science from non-science or good knowledge from bad knowledge.
Instead, he wanted to show how groups of people come to hold certain beliefs, regardless of
whether they are scientifically correct.
➞ Bloor’s sociological reductionism explains science as a social phenomenon, focusing on why
people believe things rather than whether those beliefs are true.
7 The practice-turn in the philosophy of science (roughly starting with Kuhn)
Shifts focus from abstract theories about what science is to the actual practices of scientists.
Instead of asking what makes science scientific (like verificationists, Popper, or Lakatos did), this
approach studies how science is done in daily life — how scientists experiment, collaborate,
publish, and communicate.
It looks at concrete activities such as:
- publication and peer review processes,
- laboratory work,
- how social factors (like gender or power) influence research.
The practice turn treats science as a collection of diverse, local practices, not one unified method.
It also inspired areas like feminist philosophy of science and science studies, which examine how
scientific knowledge is produced and maintained.
➞ The practice turn focuses on what scientists actually do — studying the real, practical, and
social processes that shape scientific knowledge.
6
PHILOSOPHY OF SCIENCE
PROF. COLIN JAKOB RITTBERG
PSYCHOLOGIE
1E BACHELOR
VUB
,Inhoudsopgave
Chapter 1 – Introduction ......................................................................................................................... 4
1 Historical overview: normative approaches and the practice turn .............................................................. 4
2 Science is great ....................................................................................................................................... 7
3 Knowledge as justified true belief (JTB account of knowledge) .................................................................... 8
4 Scientific justifications are special ........................................................................................................... 8
Chapter 2 – The demarcation problem (Ladyman; chapters 1-3) (Hacking; Introduction) .......................... 10
1 Why does demarcation matter? ............................................................................................................. 10
2 Deductive and Inductive reasoning ......................................................................................................... 12
3 Naïve vertificationism ............................................................................................................................ 13
3.1 Naïve verificationism’s answer to the demarcation problem .............................................................. 14
3.2 Is naïve verificationism convincing? ................................................................................................. 14
3.3 Does the inductive method produce knowledge? .............................................................................. 14
3.4 The problem of induction ................................................................................................................. 15
4 The demarcation problem in 1900 .......................................................................................................... 16
5 Confirmationism ................................................................................................................................... 16
5.1 Popper on Marxism and psychoanalysis ........................................................................................... 16
5.2 Good scientific theories (according to Popper).................................................................................. 17
6 Falsificationism (Popper) ....................................................................................................................... 17
7 Impact .................................................................................................................................................. 18
7.1 On truth .......................................................................................................................................... 19
Chapter 3 – Towards Historicism: the geocentrism/heliocentrism case study (Ladyman; chapter 4.4) ..... 20
1 The Ptolemaic System – Geocentrism..................................................................................................... 20
1.1 Intellectual Background ................................................................................................................... 20
1.2 Claudius Ptolemy ............................................................................................................................ 20
1.3 Circles upon circles ......................................................................................................................... 20
2 Heliocentrism ....................................................................................................................................... 22
2.1 Copernicus (1473–1543) .................................................................................................................. 22
2.2 Tycho Brahe (1546–1601) ................................................................................................................. 23
2.3 Johannes Kepler (1571–1630) ........................................................................................................... 24
2.4 Galileo Galilei (1564–1642) .............................................................................................................. 24
2.5 Relevant take-aways........................................................................................................................ 26
3 Case studies as a method (Not relevant for exam, useful for deeper understanding) ................................. 27
3.1 Methodological debate .................................................................................................................... 27
Chapter 4 – Scientific rationality in practice (Ladyman; chapter 4) .......................................................... 28
1 Thomas Samuel Kuhn (1922 – 1996) ....................................................................................................... 28
1.1 Why does Khun matter? ................................................................................................................... 28
1.2 Against “theory talk” ........................................................................................................................ 28
2 Paradigms ............................................................................................................................................ 29
2.1 Paradigms as the Constellation of Group Commitments ................................................................... 29
2.2 Paradigms as Shared Examples ....................................................................................................... 30
3 The four phases of scientific development .............................................................................................. 30
3.1 Pre-paradigmatic phase: Before there is a shared paradigm .............................................................. 31
3.2 Normal Science: Science under a dominant paradigm ...................................................................... 32
3.3 Crisis: When the paradigm begins to break down .............................................................................. 33
3.4 Revolution: Paradigm shift - a new framework replaces the old.................................................... 33
1
, 4 Incommensurability .............................................................................................................................. 34
5 The Popper-Kuhn debate ....................................................................................................................... 35
5.1 Is science cumulative and objective, or revolutionary and socially embedded? ............................ 35
6 Post-Khun: The practice-turn in the philosophy of science ....................................................................... 36
Chapter 5 – Practicing scientific rationality (Hacking; chapter 8)............................................................. 38
1 Imre Lakatos (1922-1974) ...................................................................................................................... 38
1.1 Some original sources ..................................................................................................................... 38
1.2 Content & Structure of Lakato’s lecture ............................................................................................ 40
1.3 Where to situate Lakatos on the normative/descriptive divide in the PhiSci? ...................................... 40
1.4 Scientific research programmes (SRP).............................................................................................. 41
2 Paul Feyerabend (1924-1994) ................................................................................................................ 44
2.1 Theoretical Anarchism ..................................................................................................................... 45
2.2 Anything goes .................................................................................................................................. 45
2.3 Proliferation of theory ...................................................................................................................... 46
2.4 Galileo and the church .................................................................................................................... 48
2.5 Context of discovery & Context of Justification .................................................................................. 48
Chapter 6 – Philosophy of mathematics ................................................................................................ 50
1 Genesis of the paper.............................................................................................................................. 50
1.1 From epistemic injustice to epistemic exclusion ............................................................................... 50
Practices and justified exclusion: .......................................................................................................... 50
2 The Phenomenon .................................................................................................................................. 51
2.1 Community conception of ‘cranks’................................................................................................... 51
2.2 What about it? ................................................................................................................................. 52
3 Time management is nothing new .......................................................................................................... 54
3.1 Standard Academic Publishing ........................................................................................................ 54
1.2 Time management: reviewing strategies in mathematics ................................................................... 55
4 Crank ≠ Crank: teasing apart the concept ............................................................................................... 55
4.1 Manifest and operative concepts ..................................................................................................... 55
5 Some insights ....................................................................................................................................... 56
Chapter 7 – Feminist philosophy of science ........................................................................................... 57
1 Four waves of feminism ......................................................................................................................... 57
2 Themes in feminist philosophy of science ............................................................................................... 57
2.1 The ideal of value-free science ......................................................................................................... 57
2.2 Standpoint Theory ........................................................................................................................... 58
2.3 José medina .................................................................................................................................... 58
2.4 Problems with (early) feminist in PhilSci ........................................................................................... 58
3 Helen Logino on objectivity in science .................................................................................................... 59
3.1 Strategy 1: Critiques of science Itself ................................................................................................ 59
3.2 Strategy 2: Critiques of Philosophy of Science and Rationality ........................................................... 60
3.3 Strategy 3: Critiques of the Institutional and Aocial Structures of Science .......................................... 60
3.4 Longino’s concern ........................................................................................................................... 61
3.5 Four Criteria for Objectivity (Longino) ............................................................................................... 62
3.6 Summary ........................................................................................................................................ 63
3.7 Criticism Longino’s account of Objectivity ........................................................................................ 63
Chapter 8 – Realism vs Anti-realism (Hacking; chapter 1) ....................................................................... 64
1 Metaphysics ......................................................................................................................................... 64
1.1 Realism vs. anti-realism .................................................................................................................. 64
1.2 Entity (anti-)realism and theory (anti-)realism ................................................................................... 66
2
, 1.3 Hacking: if you can intervene on it, then it’s real ................................................................................ 67
Chapter 9 – Philosophy of Mind ............................................................................................................. 69
1 Mind-Body Dualism ............................................................................................................................... 69
1.1 Descartes ....................................................................................................................................... 69
2 Behaviourism (Gilbert Ryle (1900–1976) & Rudolf Carnap (1891–1970)) .................................................... 71
3 Identity Theory ...................................................................................................................................... 72
4 Functionalism ....................................................................................................................................... 73
5 The Hard Problem (Chalmers, 1996) ....................................................................................................... 74
Chapter 10 – Philosophy of Technology ................................................................................................. 76
1 What is a technology? ............................................................................................................................ 76
1.1 Technologie as practice ................................................................................................................... 76
1.2 Technology as a system ................................................................................................................... 76
2 Technology = applied science? .............................................................................................................. 77
3 Values and Technology .......................................................................................................................... 77
4 AI and scientific explanation .................................................................................................................. 78
Voorbeeld vragen examen .................................................................................................................... 79
3
,Chapter 1 – Introduction
1 Historical overview: normative approaches and the practice turn
1 Layman’s verificationism (1900-today)
The simple idea that science works by verifying things — that we can prove or confirm whether
something is true.
For example: proving that atoms exist, that smoking causes cancer, or that climate change is real.
Two Problems:
- The problem of induction: we can only observe a limited number of cases (e.g. all swans
we’ve seen are white), but that doesn’t prove all swans are white. We can’t verify
everything.
- The historical problem: if theories are truly verified, why do we later replace them? For
instance, Newton’s physics was once seen as true, but Einstein showed it was incomplete.
➞ Layman’s verificationism is a naive belief that science can fully prove things true, while in
reality, scientific knowledge is always limited and changeable.
2 Popper’s falsificationism (1930s)
Science cannot prove a theory true — it can only test it and try to show it’s false.
A theory is scientific if it can be falsified:
- Scientists make predictions based on a theory.
- If observations go against those predictions, the theory is falsified and must be revised or
rejected.
- If no falsifying evidence appears yet, we keep the theory for now — but it’s never proven
true.
This idea helps separate science from non-science.
For example: evolution can be tested and possibly disproven (so it’s scientific), while creationism
or astrology cannot be falsified (so they are not scientific).
➞ Falsificationism means science advances by eliminating false theories, not by proving true
ones.
4
,3 Kuhn’s historicism (1960s)
Focuses on how science actually works in practice, rather than how it should work in theory.
Kuhn noticed that scientists do not behave the way Popper described — they don’t constantly try
to falsify their own theories. Instead, most scientists work within an accepted paradigm (a shared
framework of ideas and methods). Over time, new discoveries can cause a scientific revolution,
where one paradigm is replaced by another (for example, Newtonian physics → Einstein’s
relativity).
Unlike Popper, Kuhn doesn’t try to solve the demarcation problem (what counts as real science).
He doesn’t define what science is, but rather describes how it changes over time — based on
history.
➞ Kuhn’s historicism sees science as a historical and social process that evolves through
paradigm shifts, not through strict falsification or verification.
4 Lakatos’s rational reconstructions (later 1960s)
Tries to combine Popper’s and Kuhn’s ideas.
Like Kuhn: Lakatos believed philosophy of science must stay close to how science really happens
— not just abstract theory.
Like Popper: he thought it’s still important to find a demarcation criterion: a way to tell good
science from bad science.
Lakatos said we shouldn’t judge single theories but rather research programs — groups of related
theories that evolve over time. A program is scientifically strong if it leads to new discoveries and
predictions; it’s weak or degenerating if it only explains past results without progress.
➞ Lakatos’s rational reconstructions combine realism about how science works (like Kuhn) with
Popper’s goal of distinguishing progressive from non-scientific research.
5 Feyerabend’s methodological anarchism (1970s)
Rejects the idea that there is one correct scientific method.
He argued that every rule philosophers make to define what counts as real science eventually fails
when you look at history — because scientists have always broken the rules and still made
progress. That’s why he famously said: “Anything goes.”
5
, In his book Against Method, Feyerabend claimed that trying to impose strict methods or
boundaries on science limits creativity and discovery. Instead, science advances through freedom,
diversity, and even chaos, not through fixed procedures.
➞ Feyerabend’s methodological anarchism says there is no single scientific method — successful
science often ignores the rules philosophers try to create.
6 Bloor’s sociological reductionism (1970s)
Focuses on explaining scientific beliefs through social factors, not through truth or falsity.
Bloor, founder of the Strong Programme in Edinburgh, argued for the principle of symmetry: both
true and false beliefs should be explained in the same sociological way — by looking at culture,
interests, power, and context.
He didn’t try to separate science from non-science or good knowledge from bad knowledge.
Instead, he wanted to show how groups of people come to hold certain beliefs, regardless of
whether they are scientifically correct.
➞ Bloor’s sociological reductionism explains science as a social phenomenon, focusing on why
people believe things rather than whether those beliefs are true.
7 The practice-turn in the philosophy of science (roughly starting with Kuhn)
Shifts focus from abstract theories about what science is to the actual practices of scientists.
Instead of asking what makes science scientific (like verificationists, Popper, or Lakatos did), this
approach studies how science is done in daily life — how scientists experiment, collaborate,
publish, and communicate.
It looks at concrete activities such as:
- publication and peer review processes,
- laboratory work,
- how social factors (like gender or power) influence research.
The practice turn treats science as a collection of diverse, local practices, not one unified method.
It also inspired areas like feminist philosophy of science and science studies, which examine how
scientific knowledge is produced and maintained.
➞ The practice turn focuses on what scientists actually do — studying the real, practical, and
social processes that shape scientific knowledge.
6
