Part I: What Is Science?
Chapters 1–3: The Demarcation Problem, The Scientific Method, and Observation & Theory-Ladenness
The question “What is science?” may seem straightforward, but it has proven to be one of the most intractable problems in philosophy. Science is perhaps the most successful cognitive enterprise in human history — it has put humans on the moon, eradicated smallpox, and revealed the age of the universe — yet philosophers have struggled for centuries to articulate precisely what makes science science.
Part I of this course tackles this foundational question from three complementary angles. First, we examine the demarcation problem: the challenge of drawing a principled boundary between science and non-science (or pseudoscience). Second, we investigate whether there is a single scientific method that all sciences share, or whether the unity of science is a myth. Third, we confront the unsettling claim that observation itself istheory-laden — that there is no neutral vantage point from which to adjudicate between rival theories.
Together, these three chapters lay the groundwork for everything that follows. The debates introduced here — about falsifiability, paradigms, underdetermination, and the objectivity of observation — will recur throughout the entire course.
The Central Question
Why does the question “What is science?” matter? It is not merely an academic exercise. The demarcation between science and non-science has profound practical consequences. Courts must decide whether “creation science” belongs in biology classrooms. Governments must decide which research programmes to fund. Medical regulators must determine which therapies count as evidence-based. Patients must distinguish legitimate treatments from quackery.
The philosopher Larry Laudan famously declared the demarcation problem dead in 1983, arguing that no single criterion could do the job. But the problem refuses to stay buried. In an age of climate denialism, anti-vaccine movements, and the replication crisis, the question of what distinguishes good science from bad science — and science from pseudoscience — is more urgent than ever.
“The criterion of the scientific status of a theory is its falsifiability, or refutability, or testability.”— Karl Popper, Conjectures and Refutations (1963)
Popper’s answer is the most famous, but as we shall see, it is far from the last word. Kuhn, Lakatos, Laudan, Feyerabend, and many others have offered competing accounts — each illuminating a different facet of the problem.
Historical Context
The word “science” (from Latin scientia, meaning knowledge) originally referred to any systematic body of knowledge. Aristotle’s Posterior Analytics laid down conditions forepisteme — demonstrative knowledge derived from first principles through syllogistic reasoning. For Aristotle, science was about certain knowledge of the causes of things.
The Scientific Revolution of the 16th and 17th centuries transformed both the practice and the self-understanding of science. Francis Bacon championed systematic observation and induction. Galileo demonstrated the power of mathematical description and controlled experiment. Newton’sPrincipia became the paradigm of what science could achieve. Yet even Newton titled his masterwork Mathematical Principles of Natural Philosophy — the term “scientist” was not coined until 1833, by William Whewell.
By the early 20th century, the logical positivists of the Vienna Circle attempted to provide a rigorous criterion for distinguishing meaningful (scientific) statements from meaningless (metaphysical) ones. Their verification principle — the subject of Part II — was the first systematic attempt at demarcation. Its failure set the stage for Popper, Kuhn, and the debates that dominate modern philosophy of science.
Chapters in Part I
The Demarcation Problem
What distinguishes science from non-science and pseudoscience? We examine the major proposed criteria — from Popper’s falsifiability to Kuhn’s puzzle-solving to Lakatos’s progressive research programmes — and apply them to controversial cases like astrology, string theory, and intelligent design.
The Scientific Method
Is there a single scientific method? We compare the hypothetico-deductive method, inference to the best explanation, and Bayesian reasoning. We examine Feyerabend’s radical thesis that science has no fixed method at all, and consider how method varies across the natural and social sciences.
Observation & Theory-Ladenness
Can observation provide a neutral foundation for science? Hanson, Kuhn, and Churchland argue that what we see is shaped by what we believe. Fodor offers a partial defence of observational autonomy. We examine the implications for scientific objectivity and the possibility of crucial experiments.
Key Themes Across Part I
The Unity of Science
Is there something that all sciences share — a method, a subject matter, a set of epistemic virtues? Or is “science” a family-resemblance concept with no essential core? This question runs through all three chapters.
Normativity vs Description
Should philosophy of science prescribe how science ought to work (Popper, the positivists), or describe how it actually works (Kuhn, Feyerabend)? The tension between normative and descriptive approaches shapes every debate in this part.
The Role of Theory
Theories are not just products of science — they shape the very observations on which science depends. Understanding the relationship between theory and observation is crucial for grasping both the power and the limitations of scientific knowledge.
Practical Stakes
These are not idle philosophical puzzles. They bear directly on how we evaluate climate science, vaccine research, forensic evidence, and social science methodology. The demarcation problem has been litigated in courtrooms and debated in legislatures.
Key Philosophers in Part I
| Philosopher | Key Contribution | Chapter |
|---|---|---|
| Karl Popper | Falsifiability as demarcation criterion | 1, 2 |
| Thomas Kuhn | Paradigms, puzzle-solving, theory-laden perception | 1, 3 |
| Imre Lakatos | Research programmes (progressive vs degenerating) | 1 |
| Paul Feyerabend | Epistemological anarchism (“Against Method”) | 2 |
| N.R. Hanson | Theory-ladenness of observation | 3 |
| Paul Churchland | Cognitive penetrability of perception | 3 |
| Jerry Fodor | Modularity and defense of observation | 3 |
Essential Readings
- •Popper, K. (1963). Conjectures and Refutations, Chapter 1: “Science: Conjectures and Refutations.”
- •Kuhn, T. (1962/1996). The Structure of Scientific Revolutions, Chapters 1–5.
- •Lakatos, I. (1978). The Methodology of Scientific Research Programmes, Chapter 1.
- •Feyerabend, P. (1975). Against Method, Chapters 1–4.
- •Hanson, N.R. (1958). Patterns of Discovery, Chapter 1: “Observation.”
- •Laudan, L. (1983). “The Demise of the Demarcation Problem,” in Physics, Philosophy, and Psychoanalysis.
- •Fodor, J. (1984). “Observation Reconsidered,” Philosophy of Science 51(1).
Guiding Questions for Part I
- Is there a sharp boundary between science and pseudoscience, or is the distinction a matter of degree?
- Can a single criterion (falsifiability, verifiability, puzzle-solving) demarcate science from non-science?
- What role do experiments play in scientific knowledge? Are they the defining feature of science?
- Is there a “scientific method” that all sciences share, or is Feyerabend right that “anything goes”?
- If observation is theory-laden, how can evidence ever settle disputes between rival theories?
- Does the replication crisis undermine the authority of science, or is it a sign that science is self-correcting?
- What are the practical consequences of failing to distinguish science from pseudoscience?