Explanation
Horismus is a concise definition that determines a concept especially through its boundary from neighbouring concepts. Rather than listing every property, it identifies the decisive difference: what must be present, and what prevents confusion with a similar phenomenon? Concision makes concepts usable, but can also fix contested boundaries as self-evident. Analysis establishes the superordinate field and neighbouring terms, formulates the differentiating feature, and tests it against positive, negative, and borderline cases. A sound horistic definition must remain brief without becoming circular or covertly evaluative.
Movement of thought
1. The shared superordinate field of the concept and its nearest neighbours is established. 2. The proposed differentiating feature is formulated concisely and without circularity. 3. Clear positive and negative cases test whether the boundary includes and excludes as intended. 4. Borderline cases and counterexamples reveal needs for added conditions or graded transitions. 5. A final concise formula is tested for precision, neutrality, applicability, and historical range.
Scientific use case
Conceptual history, philosophy of science, terminology, legal doctrine, and ontology engineering use horistic definitions for operational distinctions. Quality tests assess inter-annotator agreement and misclassification at boundary cases.
Example
A methods course defines, “Correlation is a statistical association, not a claim that changing one variable causes the other.” The neighbouring concept of causation supplies the boundary.
Counterexample
A synonym list, etymological note, or extended description is not horismus. A concise conceptual determination by a genuinely differentiating feature is required.
Distinction
Distinguish horismus from real definition, nominal definition, etymology, and extended descriptio. Horismus foregrounds concise demarcation from the nearest term; other definitions may develop origin, essence, or usage more broadly.
Effect on thought and perception
Horismus creates rapid conceptual orientation and makes categories testable. An overly rigid or interested boundary formula may conceal transitions and close debate prematurely.
Resonance
A concept gains contour through the neighbours from which it differs. Meaning arises not in isolation but as a tensioned boundary within a field of similar possibilities.
Cite this entry
Reich, Michael (Hrsg./ed.): „Horismus“. Atlas der Sprache, AT-HAR6-0011. ATLAS 260, data model 1.6.0. https://atlasoflanguage.com/concept/AT-HAR6-0011The address remains stable; editorial content may evolve. Editorial reading state: 2026-10-15. Include your access date for precise references.
Historical background
Under the spelling Horysmos, Peacham treats definition as a way to distinguish neighbouring evaluations. His opening contrast separates courage from rashness by reference to the reasons for facing danger. Subsequent examples show that such distinctions can themselves be contested: speakers may offer competing accounts of what makes a victory glorious. The historical operation is therefore not simply attaching a dictionary meaning to a word. It proposes a criterion through which actions will be judged. In an original Atlas test, distinguishing persistence from obstinacy requires asking whether contrary evidence can change the agent's course. The preferred label does not settle that question. The entry supplies an English Renaissance witness, while the relation between Horysmos, Horismos and the inherited English lemma Horismus remains a lexical editorial task.
How conceptual history changes the analysis
Horismus draws an evaluative boundary by an explicit criterion; the preferred name alone does not show that the criterion is sound or uncontested.