The civilizing mission (misión civilizadora; Missão civilizadora; Mission civilisatrice) is a political rationale for military intervention and for colonization purporting to facilitate the Westernization of indigenous peoples, especially in the period from the 15th to the 20th centuries. As a principle of Western culture, the term was most prominently used in justifying French colonialism in the late-15th to mid-20th centuries. The civilizing mission was the cultural justification for the colonization of French Algeria, French West Africa, French Indochina, Portuguese Angola and Portuguese Guinea, Portuguese Mozambique and Portuguese Timor, among other colonies. The civilizing mission also was a popular justification for the British, German, and American colonialism. In the Russian Empire, it was also associated with the Russian conquest of Central Asia and the Russification of that region. The Western colonial powers claimed that, as Christian nations, they were duty bound to disseminate Western civilization to what they perceived as heathen, primitive cultures.
The civilizing mission originated in the Christian theology of the Middle Ages, when European theologists applied the metaphor of human development to misrepresent social change as a law of Nature. In the eighteenth century, Europeans saw history as a linear, inevitable, and perpetual process of sociocultural evolution led by capitalist Western Europe. From the reductionist cultural perspective of Western Europe, colonialists saw non-Europeans as "backward nations", as people intrinsically incapable of socioeconomic progress. In France, the philosopher Marquis de Condorcet formally postulated the existence of a European "holy duty" to help non-European peoples "which, to civilize themselves, wait only to receive the means from us, to find brothers among Europeans, and to become their friends and disciples".
Modernization theory — progressive transition from traditional, premodern society to modern, industrialized society — proposed that the economic self-development of a non-European people is incompatible with retaining their culture (mores, traditions, customs).