Quaternio

Quaternio is a term with several distinct meanings, primarily found in historical and academic contexts. One significant usage of quaternio refers to a specific type of medieval manuscript gathering. In manuscript production, a quaternio was a quire or gathering consisting of four sheets of parchment or paper, each folded once to create eight leaves. These sheets were typically nested within each other and then stitched together to form a booklet or section of a larger codex. The term derives from the Latin word for "four," reflecting the number of sheets.

Beyond manuscript studies, quaternio also has a historical meaning related to Roman military organization. It denoted a division of a legion typically comprising four soldiers. This arrangement was a fundamental unit for tactical maneuvers and camp organization.

In a more specialized sense, particularly within certain theological and philosophical traditions, quaternio can refer to a structured argument or explication that proceeds through four distinct points or stages. This method of exposition emphasizes thoroughness and a systematic approach to a subject. The application of the term quaternio highlights a common historical practice of organizing information or units into groups of four.