The concept of Social Darwinism was a widely accepted theory in the 19th century. Various intellectual and political figures from each side of the political spectrum have grasped the theory and interpreted it in various ways. In this article, we will discuss three different thinkers from the 19th century and their conception of Social Darwinism. The conservative Heinrich von Treitschke and the liberal Herbert Spencer both made arguments about the usefulness of competition between people on a global scale. Anarchist Peter Kropotkin refuted the belief in constant competition between members of the same species and emphasized mutual aid. Heinrich von Treitschke's defense of Social Darwinism was a direct result of his vision of the state and the nation. He believed that only brave nations could stand the test of time and asserted that nations that failed to demonstrate their might would eventually be preyed upon and parished. Treitschke makes this clear when he says: “The story has typically masculine features; it is not for sentimental natures nor for women. Only courageous nations have a secure existence, a future, development; weak and cowardly nations are going to the wall, and rightly so. (Treitschke, 11). He believed that competition between nations reflected the superiority of the winner. Treitschke proclaimed that there were two main functions of the state, the second being for the state to wage war and the most important for understanding its defense of Social Darwinism. He believed that only through war would a great nation succeed. In his thinking, he takes up the idea of ​​competition between animals defended by Darwin and places them on a global scale where nations compete for superiority. Competition between nations was the only way to gain access to the middle of the paper society. He gave the example of unions, voluntary associations and grassroots societies. For Heinrich von Treitschke, conflict was necessary to forge great states and strengthen society. Historical progress is the result of war, which eliminated the weakest from society. In a similar vein, Herbert Spencer believed that war was a force that advanced society and cleansed the inferior and weak people of the world. Peter Kropotkin rejected these interpretations of Darwin's theory and argued that sociability and cooperation were the true strengths of all species. Each argument reflected the broader worldview these men had due to their respective ideologies. Treitschke based his view on the tradition of war, Spencer did much the same but refuted war because of its need for subordination, and Kropotkin focused on the inherent cooperation of individual species..