Frederick Engels argues that materialism provides a unified framework for understanding natural processes. Engels asserts that all facts, including those about the human mind, are causally dependent on physical processes, unlike idealism which posits consciousness as primary. Engels cites 19th century scientific advances like Wohler's synthesis of organic molecules from inorganic ones as disproving vitalism and establishing a materialist understanding of life. Darwin's theory of evolution by natural selection similarly explained the origins of organisms through physical laws rather than mystical forces. For Engels, scientific discoveries had explained nature as a system of interconnected physical processes, validating the materialist worldview.