"The answers given by ethics determine how man should treat other men, and this determines the fourth branch of philosophy: politics, which defines the principles of a proper social system. As an example of philosophy’s function, political philosophy will not tell you how much rationed gas you should be given and on which day of the week — it will tell you whether the government has the right to impose any rationing on anything."
Ayn Rand, Philosophy: Who Needs It, 4