causes

A cause is an event, condition, or factor that brings about an effect or outcome. In many fields, causes are identified to explain why something happened and to predict what might happen under similar circumstances.

Causes can be categorized as proximate (immediate mechanisms that directly trigger an effect) or ultimate (underlying reasons or historical factors). They can also be described as necessary conditions, sufficient conditions, or combinations thereof.

Many outcomes arise from multiple causes that interact. Some factors are direct causes, while others are indirect, influencing the effect through intermediary steps. Some causes are both necessary and sufficient, others neither.

A key distinction is between causation and correlation. Correlation is an association between events, while causation implies that altering the cause would change the outcome. Establishing causation relies on evidence from experiments or robust observational methods.

Methods to infer causation include randomized controlled trials, natural or quasi-experiments, longitudinal analyses, and statistical techniques that account for confounding. Counterfactual reasoning—considering what would have happened in the absence of a factor—also underpins causal claims.

Causes are central in science, medicine, law, and policy, guiding interventions and explanations. They are subject to uncertainty, measurement error, and context dependence; complex systems often involve many interacting causes, making precise causal attribution challenging.