årsag

Årsag is the Danish term for "cause" and denotes the reason or antecedent that makes an event or condition occur. It is used across everyday language, medicine, science, law and philosophy to identify what drives a particular outcome.

In philosophy and science, causes can be categorized in several ways. A necessary cause is something that must be present for the effect to occur, though it may not be enough on its own. A sufficient cause can produce the effect by itself but need not be the only possible cause. In most real situations, multiple interacting causes are involved, spanning proximal (immediate) and distal (farther) factors, with a network of contributory causes rather than a single root.

Causal inference aims to establish that a cause truly leads to an effect, not merely that the two variables move together. Researchers use experiments, such as randomized controlled trials, and observational approaches, including longitudinal studies, natural experiments and instrumental variables, to address confounding, bias and alternative explanations.

Examples of causes span many domains. Smoking is a well-established cause of lung cancer; a broken brake line can be a proximate cause of a vehicle accident; low socioeconomic status is associated with various health outcomes as a contributory factor among many. In physical sciences, forces such as gravity are considered causal factors in the motion of bodies.

In Danish usage, årsag is a common word in both formal and informal contexts for discussing the reasons behind events, decisions and policies.