dichotomy

What it means

1. countableuncountableA separation or division into two; a distinction that results in such a division.

   The dichotomy between maria and highlands dominates lunar mineralogy.

   2003, Thérèse Encrenaz et al., “The Solar System”, in Storm Dunlop, transl., Système Solaire, page 232

   3 more examples

   The dichotomy between the private and the public is central to almost two centuries of feminist writing and political struggle; it is, ultimately, what the feminist movement is all about. Although some feminists treat the dichotomy as a universal, trans-historical and trans-cultural feature of human existence, feminist criticism is primarily directed at the separation and opposition between the public and private spheres in liberal theory and practice.

   1989, Carole Pateman, 6: Feminist Critiques of the Public/Private Dichotomy: The Disorder of Women: Democracy, Feminism, and Political Theory, page 118

   Despite some contradictions found in the essay, its major emphasis is laid on the politics-administration dichotomy theory. It is largely devoted to the argument concerning the separability of politics and administration. The politics-administration dichotomy initiated by Wilson was later elaborated by Frank J. Goodnow in his work, “Politics and Administration” (1900).

   2005, S. P. Naidu, Public Administration: Concepts And Theories, page 55

   All of this previous analysis was based on two related ideas: the classical dichotomy and monetary neutrality. Recall that the classical dichotomy is the separation of variables into real variables (those that measure quantities or relative prices) and nominal variables (those measured in terms of money).

   2008, N. Gregory Mankiw, Principles of Economics, 6th edition, page 723

   Synonyms: bisection

2. countableuncountableSuch a division involving apparently incompatible or opposite principles; a duality.

   Slavery flourished, and absolute centralisation of power did not permit European-style feudalism until very late and only in some cases. “The Eurasian dichotomy of suzerain versus subject left little room in between.”

   2026 August 29, Charles Clover, “Russia vs the west”, in FT Weekend (Life & Arts section), London: The Financial Times Ltd., →ISSN, →OCLC, page 9

   1 more example

   But we do not try to characterize the top and bottom parts of the brain in terms of a simple dichotomy or set of dichotomies, which was exactly what was done with the existing and well-known division of the brain into two halves: namely the left versus the right, the dominant pop-culture brain story of the last few decades. […] The dif­ferences between the left and right sides of the brain are nuanced, and simple, sweeping dichotomies do not in fact explain how the two sides function.

   2013 November 11, Stephen M. Kosslyn, G. Wayne Miller, “How the Brain Creates Personality: A New Theory”, in The Atlantic

3. countableuncountablehuman sciencesThe division of a class into two disjoint subclasses that are together comprehensive, as the division of human into female and male.

   But in the fallacy of false dichotomy, not only do the two alternatives fail to be jointly exhaustive, but they are not even likely. As a result, the disjunctive premise is false, or at least probably false.

   2011, Patrick J. Hurley, A Concise Introduction to Logic, page 162

   1 more example

   2011, Tomasz A. Gorarzd, Jacek Krzaczkowski, The Complexity of Problems Connected with Two-Element Algebras, Paweł M. Idziak, Andrzej Wronski, Reports on Mathematical Logic: No. 46, page 92, One can ask if for any algebra the considered problem is always in P or NP-complete (P or coNP-complete)? For example, the problem of the satisfiability of a system of polynomial equations over a group G is in P if G is abelian and NP-complete otherwise ([7, 13]). One of the most widely known subclasses of NP which exhibits such a dichotomy, is the class of constraint satisfaction problems (CSP) on the set {0,1}, see [16]. Recently Bulatov proved the dichotomy for CSP on a three-element set [3].

In a sentence

The dichotomy between maria and highlands dominates lunar mineralogy.

2003, Thérèse Encrenaz et al., “The Solar System”, in Storm Dunlop, transl., Système Solaire, page 232

Where it comes from

1. Ancient Greekδιχοτομία“dichotomy”
2. Englishdichotomy

From Ancient Greek διχοτομία (dikhotomía, “dichotomy”).