Final answer:
According to Plutarch, the Spartans justified killing helots to maintain their security and dominance in Sparta by suppressing the enslaved population who they feared might rebel.
Step-by-step explanation:
According to Plutarch, the Spartans justified killing helots by claiming that it was necessary for their own security and to maintain their position as the dominant power in Sparta. The helots were the enslaved population in Sparta, and the Spartans feared their potential rebellion due to their larger numbers. By suppressing the helots through violence, the Spartans believed they could prevent any uprisings and maintain control over their city-state.
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