Incidentalness

Incidentalness is the quality of being incidental: occurring as a secondary, nonessential, or fortuitous aspect of something. An incidental feature is not central to the main purpose, function, or identity of the thing it accompanies, and it may vary without changing what the thing essentially is.

In philosophy, incidental (or accidental) properties contrast with essential properties. A thing’s essence comprises its defining attributes; incidental properties are those that may vary between instances and do not alter the thing’s identity. This distinction traces to Aristotle and remains common in contemporary metaphysics and philosophy of science.

In everyday language, incidental can describe effects or details that accompany a primary activity. Incidental expenses are costs arising in connection with a project but not part of its main budget. Incidental findings are observations discovered unintentionally in medical testing.

In the arts, incidental music is composed to accompany a drama or narrative without being part of the work’s main text. The term is also used in law and policy to indicate secondary or peripheral consequences or provisions.

Incidentalness is context-dependent: what counts as incidental depends on the framework of analysis, as opposed to what is essential. See also essential property, accidental, contingent property, incidental music, incidental findings.