pääsyy

Pääsyy is a Finnish noun meaning the main reason or primary cause of something. It is used in analysis, journalism, and everyday language to indicate the factor that most significantly explains a situation. The term combines pää, meaning "main" or "head," with syy, meaning "cause."

In practice, pääsyy marks the principal causal factor among several possible contributors. It is often discussed alongside notions of secondary or contributing causes. In investigative contexts, identifying the pääsyy may require data collection, evidence, and reasoning, and it is sometimes distinguished from perimmäinen syy, which refers to the ultimate or deeper root cause.

Usage examples illustrate its role in reasoning about events or problems. For instance, a report might state that the main reason for a malfunction was an electrical fault, while a safety assessment might seek to identify the most significant factor to address. The term is common in fields such as engineering, safety analysis, quality control, and policy discussions.

Related terms include päätekijä (the principal factor) and perimmäinen syy (the ultimate root cause). Pääsyy is often contrasted with broader or ancillary causes, focusing on the factor with the strongest explanatory power for the observed outcome.

See also: root cause analysis, Ishikawa diagram, syy, tekijä.