perussyyyn

Perussyyyn is a fictional term introduced in discussions of causation to denote the fundamental cause or primary impetus behind a phenomenon. In these thought experiments, perussyyyn serves to separate the essential driver from secondary correlates and incidental factors, facilitating clearer analysis of why a given event or effect occurs.

The term is constructed from elements intended to evoke basic and causal meanings in a hypothetical language; it does not belong to any documented scientific vocabulary. Because it is not standard across disciplines, its precise interpretation can vary between authors, though common usage treats perussyyyn as the deepest, non-reducible cause in a causal chain.

As a theoretical entity, perussyyyn is characterized by necessity and sufficiency in the context of a model: removing the perussyyyn would prevent the outcome, while altering other factors would not, in principle, suffice to produce the effect alone. In practice, it is often treated as an abstraction rather than a directly observable object.

Perussyyyn appears in debates about reductionism, explanation, and scientific modeling. Proponents argue it helps identify core mechanisms, while critics contend that many systems have distributed or multi-factor causes that resist single foundational categorization.

Because it is deliberately schematic, perussyyyn is limited as a real-world explanatory tool and can oversimplify complex phenomena. Its primary value lies in clarifying reasoning about causation rather than in providing an empirically verifiable entity. See also: causality, explanation, fundamental cause, proximate cause, necessary condition.