In the absence of any guiding principle, politics becomes a naked struggle for power
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“The national State, largely owing to gunpowder, acquired an influence over men’s thoughts and feelings which it had not had before, and which progressively destroyed what remained of the Roman belief in the unity of civilization. This political disorder found expression in Machiavelli’s Prince. In the absence of any guiding principle, politics becomes a naked struggle for power; The Prince gives shrewd advice as to how to play this game successfully. What had happened in the great age of Greece happened again in Renaissance Italy: traditional moral restraints disappeared, because they were seen to be associated with superstition;” source