This document discusses several intellectual and social currents in the 19th century that influenced the age of imperialism, including: 1) Karl Marx's social theories and critiques of capitalism which reflected the social upheaval of the time. 2) Charles Darwin's theory of evolution by natural selection which radically changed conceptions of time and biology and led to social Darwinism and scientific racism. 3) The rise of racial nationalism, anti-Semitism, and social Darwinism in Europe which supported imperialism and notions of European/Anglo-Saxon superiority. 4) New imperialism in the late 19th century driven by economic and nationalistic motives to acquire foreign territories and resources.