Political philosophies differ in large part because they make different assumptions about human nature, or what people are like. People thus differ in their political philosophy mainly because they make different assumptions about human nature. These differences in assumptions are due to differences in what different people are like, combined with people assuming that others are roughly like themselves. The fact that different people root for different political philosophies thus is itself evidence that political philosophies which make sweeping assumptions about human nature will be too simple.
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