The conclusion of Richard Hofstadter's "Social Darwinism in American Thought" reflects on the evolution and impact of social Darwinism in American society. Initially, social Darwinism was seen as a neutral instrument, capable of supporting both individualist and collectivist ideologies. The rugged individualist interpretation of Darwinism gained prominence in the 19th century due to its alignment with the competitive and ruthless nature of American business and politics. However, this version of Darwinism was unstable and ultimately led to a backlash, particularly from the middle class, who repudiated the harsh realities of unrestrained competition. The rise of Darwinian collectivism, particularly in the context of nationalism and racism, began to gain traction as a response to domestic economic issues and international conflicts. This shift was driven by the need to justify expansion and militarism through the lens of group survival and racial destiny. However, the outbreak of World War I led to a widespread revulsion against international violence, and the notion of "racial" aggression and militarism was discredited. By the end of World War I, social Darwinism had largely disappeared as a conscious philosophy in America. While it persists in political folklore, its influence has waned. The author argues that changes in social ideas are often driven by broader economic and political shifts rather than logical or scientific criteria. The acceptance of social Darwinism is more influenced by the intellectual needs and preconceptions of social interests. In conclusion, the chapter emphasizes that biological concepts like "survival of the fittest" are inadequate for understanding society, and that social improvement is a product of technological and organizational advancements, not biological selection. It also highlights the importance of moral sanctions for the common good, independent of biological or naturalistic philosophies.The conclusion of Richard Hofstadter's "Social Darwinism in American Thought" reflects on the evolution and impact of social Darwinism in American society. Initially, social Darwinism was seen as a neutral instrument, capable of supporting both individualist and collectivist ideologies. The rugged individualist interpretation of Darwinism gained prominence in the 19th century due to its alignment with the competitive and ruthless nature of American business and politics. However, this version of Darwinism was unstable and ultimately led to a backlash, particularly from the middle class, who repudiated the harsh realities of unrestrained competition. The rise of Darwinian collectivism, particularly in the context of nationalism and racism, began to gain traction as a response to domestic economic issues and international conflicts. This shift was driven by the need to justify expansion and militarism through the lens of group survival and racial destiny. However, the outbreak of World War I led to a widespread revulsion against international violence, and the notion of "racial" aggression and militarism was discredited. By the end of World War I, social Darwinism had largely disappeared as a conscious philosophy in America. While it persists in political folklore, its influence has waned. The author argues that changes in social ideas are often driven by broader economic and political shifts rather than logical or scientific criteria. The acceptance of social Darwinism is more influenced by the intellectual needs and preconceptions of social interests. In conclusion, the chapter emphasizes that biological concepts like "survival of the fittest" are inadequate for understanding society, and that social improvement is a product of technological and organizational advancements, not biological selection. It also highlights the importance of moral sanctions for the common good, independent of biological or naturalistic philosophies.