1. The idea that a ruler can only exercise power justly when consented to by the people over which that power is. This was mainly defined by Rousseau's social contract and also defined the idea that monarchs were not appointed by God and were impotent without the approval of their people.
2.The separation of church and state. Voltaire advocated for this, seeing it as an oppressive force despite being a Christian himself. He believed that, in having a theocratical ruler, corruption was almost guaranteed. Enlightenment philosophers believed that rulers should govern based on reason rather than theology.
3.Arguably, the most influential enlightenment ideas are freedom and equality. Enlightenment philosophers believed that everyone should have basic liberties, regardless of their heritage or class. These ideas directly contributed to both the American and French revolution, and subsequently influencing Napoleon vicariously through the ideas of French revolutionaries.