Ludwig Gumplowicz (March 9, 1838, Cracow – August 20, 1909, Graz, Austria-Hungary), was a Polish sociologist,jurist and political scientist, who taught constitutional and administrative law at the University of Graz.
Gumplowicz was a child of a Polish family of Jewish origin. He and his wife, Franciska, had two sons. In 1875, Gumplowicz began studying law at the Jagiellonian University in Kraków. For a year he then went to study in Vienna returning to Kraków to receive a doctoral degree in law. In 1860, he began his journalistic career. From 1869-1874 he edited his own magazine the Kraj (the Country). Then in 1875, at the age of thirty-seven, he entered the University of Graz as a lecturer in the science of administration and Austrian administrative law. In 1882, he became an associate professor, and in 1893 a full professor. Gumplowicz then retired from academia in 1908. At the end of 1907, his health began to fail. He was diagnosed with cancer of the tongue. In 1909, he and his wife committed suicide together. 
Gumplowicz became interested in the problem of suppressed ethnic groups very early, being from a Jewish family and coming from Kraków, a city of the former Polish–Lithuanian Commonwealth, which was first partitioned and later as the Free City of Kraków annexed by Austria-Hungary. He was a lifelong advocate of minorities in the Habsburg Empire, in particular, the Slavic speakers.
Gumplowicz soon became interested in the later form of sociology of conflict, starting out from the idea of the group (then known as race). He understood race as a social and cultural, rather than a biological phenomenon. He stressed in every way the immeasurably small role of biological heredity and the decisive role of the social environment in the determination of human behavior. While attaching a positive significance to the mixing of races, he noted that pure races had already ceased to exist.:85
He saw the state as an institution which served various controlling elites at different times. In analysis, he leaned towards macrosociology, predicting that if the minorities of a state became socially integrated, they would break out in war. In his 1909 publication, Der Rassenkampf (Struggle of the Races), he foresaw world war. During his life, he was considered a Social Darwinist, mainly because of his approach to society as an aggregate of groups struggling ruthlessly among themselves for domination.:83 Nevertheless, he did not deduce his conceptions directly from evolutionary theory and criticized those sociologists (Comte, Spencer, Lilienfeld) who employed biological analogies as an explanatory principle. At the same time, he shared the naturalistic conception of history and considered humanity a particle of the universe and nature, a particle governed by the same eternal laws as the whole.
His political beliefs and his polemic character attracted many Polish and Italian students, making his theories important in Poland, Italy, and other crown states (today Croatia, Czech Republic). But the fact that he published his works in German meant that he was also an important figure in German-speaking countries. Gustav Ratzenhofer was the most prominent of those influenced by him. Gustav Ratzenhofer was the sociologist which Gumplowicz thought most highly of.
Gumplowicz had another disciple in Manuel González Prada. Prada lived in Peru and found Grumplowicz’s theories on ethnic conflict useful for understanding not only the Spanish conquest of Quechua peoples during the sixteenth century but also how the descendants of the Spanish (and other European immigrants) continued to subordinate the indigenous peoples. Most striking in this regard is González Prada’s essay "Our Indians" included in his Horas de lucha after 1924. Brazilian essayist Euclides da Cunha also acknowledges Gumplowicz's influence in the preliminary note to his influential study Os Sertões (1902), an in-depth analysis of the 1895-1989 War of Canudos between Brazil's Republican government and the residents of Canudos in the backlands of Bahia. 
In his publication, The Outlines on Sociology (1899), Gumplowicz reviews the works of Comte, Spencer, Bastian, and Lippert. He also reviews the relations of economics, politics, the comparative study of law, the philosophy oh history and the history of civilization to the science of society. Many of Gumplowicz's major works are written in German.
Sociologists influenced by him were Gustav Ratzenhofer, Albion W. Small, Franz Oppenheimer. The social scientists Émile Durkheim, León Duguit, Harold J. Laski, and others elaborated Gumplowicz's view of political parties as interest groups.  Also influenced Erazm Majewski and Mieczyslaw Szerer.  His theories were also highly influential among the first conflict theorists and inspired early theoretical work on the governance on multiethnic states. 
A criticism of Gumplowicz's work is that he presents a rather narrow interpretation of the nature of social phenomena. He placed a large emphasis on social groups as well as the sociological investigation of their conflict as a unit. In doing so, Gumplowicz minimized the importance of the individual and magnified the coercion and determination that is excepted by the group to the individual. This was further than other sociologists, such as Durkheim, Sighele, LeBon, or Trotter went. 
- Grundriss Der Sociologie / The Outlines of Sociology. (1899) Translated by Frederick W. Moore. 1975, Arno Press.
- Der Rassenkampf / The Race Struggle. (1883)
- System Socyologii (1887) - Polish
- Race and State (1875)
- TORRANCE, JOHN (1976). "The Emergence of Sociology in Austria: 1885-1935". European Journal of Sociology / Archives Européennes de Sociologie / Europäisches Archiv für Soziologie. 17 (2): 185–219. doi:10.1017/S0003975600007359. ISSN 0003-9756. JSTOR 23998748.
- Adamek, Wojciech; Radwan-Pragłowski, Janusz (2016-07-24). "Ludwik Gumplowicz: A Forgotten Classic of European Sociology". Journal of Classical Sociology. doi:10.1177/1468795X06069685.
- Kochanowski, I. (1909). "Ludwig Gumplowicz". American Journal of Sociology. 15 (3): 405–409. doi:10.1086/211789. ISSN 0002-9602.
- William M. Johnston, The Austrian Mind: An Intellectual and Social History, 1848–1938 (University of California Press, 1983), p. 175
- Ward, Lester F. (1909). "Ludwig Gumplowicz". American Journal of Sociology. 15 (3): 410–413. doi:10.1086/211790. ISSN 0002-9602.
- "Kingdom of Galicia and Lodomeria", Wikipedia, 2019-09-21, retrieved 2019-10-08
- A History of Classical Sociology. Ed. by Igor Kon. Moscow, 1989. ISBN 5-01-001102-6
- "Manuel Gonzalez Prada, "Our Indians"". evergreen.loyola.edu. Retrieved 2019-10-08.
- Os Sertões, Euclides da Cunha (2010). Retrieved 2020-08-17.
- Moore, Frederick; Gumplowicz, Ludwig (1975). The Outlines of Sociology. Arno Press.
- "Ludwig Gumplowicz | Austrian scholar". Encyclopedia Britannica. Retrieved 2019-10-08.
- Konieczny, Matthew J. (2015), "Gumplowicz, Ludwig (1838-1909)", Gumplowicz, Ludwig (1838–1909), The Wiley Blackwell Encyclopedia of Race, Ethnicity, and Nationalism, American Cancer Society, pp. 1–2, doi:10.1002/9781118663202.wberen065, ISBN 9781118663202
- Barnes, Harry E. (1919). "The Struggle of Races and Social Groups as a Factor in the Development of Political and Social Institutions: An Exposition and Critique of the Sociological System of Ludwig Gumplowicz". The Journal of Race Development. 9 (4): 394–419. doi:10.2307/29738318. ISSN 1068-3380. JSTOR 29738318.
- Collection of Gumplowicz's writings at Archive.org
- 1885 review of Grundriss der Soziologie by Émile Durkheim (in French)
- JewishEncyclopedia.com – GUMPLOWICZ, LUDWIG at www.jewishencyclopedia.com – Jewish Encyclopedia
- González Prada, Manuel. "Our Indians". 1900.