Demarcation Problem

The demarcation problem asks what separates empirical science from non-science (including pseudoscience and metaphysics). The traditional answer tied science to verification and confirming evidence — the more supporting instances, the more scientific. Popper rejected this. He noticed that theories like astrology or psychoanalysis could “explain” any observation, so confirmation was cheap and uninformative. His criterion was falsifiability: a theory is scientific only if it forbids something, exposing itself to potential refutation by experience. This rests on the logical asymmetry Critical Rationalism emphasizes — no number of confirming observations can prove “all ravens are black,” yet a single counter-instance refutes it. Demarcation was thus a corollary of dropping induction and justificationism in favor of conjectures and refutations.

CF treats demarcation as one of Popper’s genuine achievements but reframes its scope and mechanism. The deeper point is not a fence around science but a universal feature of all rational thinking: ideas progress only where they can be exposed to error correction. CF therefore generalizes falsifiability into criticism across every domain, not just empirical testing. CF also rejects Popper’s residual gradualism — that theories are more or less testable or corroborated. In binary epistemology, an idea is either refuted or non-refuted for a given goal; “degree of scientific character” is no more coherent than argument strength. So demarcation, for CF, marks the boundary of correctable ideas generally, not a special status reserved for science.