Social Darwinism is a name given to various phenomena emerging in the second half of the 19th century trying to apply the evolutionary concept of natural selection to human society. The term itself emerged in the 1880s. The term Social Darwinism gained widespread currency when used after 1944 by opponents of these earlier concepts. The majority of those who have been categorised as social Darwinists did not identify themselves by such a label.
Scholars debate the extent to which the various social Darwinist ideologies reflect Charles Darwin's own views on human social and economic issues. His writings have passages that can be interpreted as opposing aggressive individualism, while other passages appear to promote it. Some scholars argue that Darwin's view gradually changed and came to incorporate views from other theorists such as Herbert Spencer. Spencer published his Lamarckian evolutionary ideas about society before Darwin first published his theory in 1859, and both Spencer and Darwin promoted their own conceptions of moral values. Spencer supported laissez-faire capitalism on the basis of his Lamarckian belief that struggle for survival spurred self-improvement which could be inherited. An important proponent in Germany was Ernst Haeckel, who popularized Darwin's thought (and personal interpretation of it) and used it as well to contribute to a new creed, the Monist movement.
The term Darwinism was coined by Thomas Henry Huxley in his April 1860 review of "On the Origin of Species", and by the 1870s it was used to describe a range of concepts of evolution or development, without any specific commitment to Charles Darwin's theory of natural selection.
The first use of the phrase "social Darwinism" was in Joseph Fisher's 1877 article on The History of Landholding in Ireland which was published in the Transactions of the Royal Historical Society. Fisher was commenting on how a system for borrowing which had been called "tenure" had led to the false impression that the early Irish had already evolved or developed land tenure;
These arrangements did not in any way affect that which we understand by the word " tenure", that is, a man's farm, but they related solely to cattle, which we consider a chattel. It has appeared necessary to devote some space to this subject, inasmuch as that usually acute writer Sir Henry Maine has accepted the word " tenure " in its modern interpretation, and has built up a theory under which the Irish chief " developed " into a feudal baron. I can find nothing in the Brehon laws to warrant this theory of social Darwinism, and believe further study will show that the Cain Saerrath and the Cain Aigillue relate solely to what we now call chattels, and did not in any way affect what we now call the freehold, the possession of the land.