Philosophy of Science Cheat Sheet

The core ideas of Philosophy of Science distilled into a single, scannable reference — perfect for review or quick lookup.

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Quick Reference

Falsifiability

Karl Popper's criterion that for a theory to be considered scientific, it must make predictions that could, in principle, be shown to be false by observation or experiment. Falsifiability distinguishes science from pseudoscience, not by proving theories true, but by requiring that they be testable and potentially refutable.

Paradigm Shift

Thomas Kuhn's concept describing a fundamental change in the basic assumptions, methods, and accepted results within a scientific discipline. During a paradigm shift, the dominant framework (paradigm) is replaced by a new one that better accounts for anomalies the old paradigm could not explain.

Demarcation Problem

The philosophical challenge of defining clear criteria that distinguish science from non-science and pseudoscience. Various proposals have been offered, including verifiability (logical positivists), falsifiability (Popper), and puzzle-solving within paradigms (Kuhn), but no single criterion has gained universal acceptance.

Scientific Realism

The philosophical position that successful scientific theories describe the world approximately as it really is, and that the entities they posit (such as electrons, genes, and quarks) genuinely exist, even when they cannot be directly observed. Realists argue that the success of science would be miraculous if theories did not at least approximately correspond to reality.

Induction and the Problem of Induction

Induction is the reasoning process of drawing general conclusions from specific observations. The problem of induction, identified by David Hume, is that no finite number of observations can logically guarantee a universal conclusion. We cannot prove that the future will resemble the past, yet science relies heavily on inductive reasoning.

Underdetermination of Theory by Evidence

The thesis that the available empirical evidence is always compatible with more than one theory. Since multiple theories can account for the same observations, evidence alone cannot conclusively determine which theory is correct, raising questions about how scientists choose among competing theories.

Logical Positivism

A philosophical movement originating with the Vienna Circle in the 1920s-1930s that held that meaningful statements are either analytically true (true by definition) or empirically verifiable through observation. Statements that are neither were considered meaningless, which effectively excluded much of metaphysics and theology from meaningful discourse.

Theory-Ladenness of Observation

The idea, advanced by philosophers including N.R. Hanson and Thomas Kuhn, that all observation is influenced by the observer's prior theoretical commitments, expectations, and conceptual frameworks. There is no purely neutral observation; what scientists see is shaped by what they already believe.

Inference to the Best Explanation (Abduction)

A form of reasoning in which one selects the hypothesis that, if true, would provide the best explanation for the observed evidence. Unlike deduction, it does not guarantee truth, but it is widely used in science to choose among competing hypotheses based on criteria like simplicity, scope, and explanatory power.

Normal Science vs. Revolutionary Science

Thomas Kuhn's distinction between two phases of scientific activity. Normal science is the routine work of puzzle-solving within an accepted paradigm, extending and applying the paradigm's methods. Revolutionary science occurs when accumulated anomalies provoke a crisis, leading to the rejection of the old paradigm and adoption of a new one.

Key Terms at a Glance

Abduction:A form of reasoning that infers the best explanation for a set of observations. Also called inference to the best explanation.

Anomaly:An observation or result that cannot be explained by the current paradigm or theory, potentially triggering scientific crisis.

Constructive Empiricism:Bas van Fraassen's position that the aim of science is empirical adequacy rather than truth about unobservable entities.

Corroboration:In Popper's philosophy, the degree to which a theory has survived rigorous attempts at falsification. Not the same as verification or confirmation.

Deduction:Reasoning from general premises to a specific conclusion. If the premises are true, the conclusion must be true.

Demarcation Problem:The challenge of drawing a clear boundary between science and non-science or pseudoscience.

Duhem-Quine Thesis:The argument that hypotheses cannot be tested in isolation because tests always rely on auxiliary assumptions that could themselves be faulty.

Empiricism:The philosophical position that knowledge comes primarily from sensory experience and observation rather than innate ideas or pure reason.

Falsifiability:Popper's criterion that a theory is scientific only if it can, in principle, be refuted by empirical evidence.

Holism:The view, associated with Quine, that scientific theories face the tribunal of experience as a whole rather than statement by statement.

Hypothetico-Deductive Method:A method of inquiry in which hypotheses are proposed, predictions are deduced from them, and observations are made to test those predictions.

Incommensurability:Kuhn's thesis that successive paradigms are so different in their concepts and standards that they cannot be fully compared or translated into each other.

Induction:Reasoning from specific observations to general conclusions. Central to empirical science but philosophically problematic since Hume.

Instrumentalism:The view that scientific theories are tools for prediction and calculation, not literal descriptions of unobservable reality.

Kuhnian Crisis:A period when accumulated anomalies undermine confidence in the dominant paradigm, opening the way for revolutionary change.

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