skepticism

Skepticism is an approach or attitude characterized by questioning the validity of knowledge claims, demanding evidence, and resisting acceptance without robust justification. It is not cynicism, which presumes people are dishonest or malicious; skepticism aims at the reliability of beliefs and the methods used to support them. The term covers a range from cautious doubt to a disciplined method of inquiry.

Skepticism has ancient roots in Greece. Pyrrhonian skepticism urged the suspension of judgment about all propositions (epoché) to attain mental tranquility. Academic skepticism, associated with Arcesilaus and Carneades, maintained that certainty is unattainable but that some beliefs are more plausible than others. Later figures such as Sextus Empiricus compiled skeptical arguments that influenced later philosophy.

In modern discourse, skepticism splits into philosophical skepticism about the possibility of knowledge and scientific or empirical skepticism that assesses claims by evidence and reasoning. Scientific skepticism applies critical thinking to test claims, especially extraordinary or pseudoscientific ones, emphasizing falsifiability, reproducibility, and cautious inference. Public figures such as Carl Sagan popularized the maxim that extraordinary claims require extraordinary evidence.

Other distinctions include global versus local skepticism (whether knowledge is possible at all versus within specific domains), and methodological versus epistemic skepticism. Skepticism intersects with science, religion, politics, and media, shaping debates about its role in education and public life. Critics argue that excessive skepticism can impede action, while proponents argue that careful doubt reduces error.

Skepticism remains a central concept in epistemology and science, informing how claims are evaluated, tested, and communicated.