Reason, resulting in emphasizing rational and scientific thought over superstition or mysticism. In France this led to suppression of the Catholic Church following the 1789 French Revolution, in American the constitutional principle separating Church and State/Government.
It also led to questioning the "divine" rights of kings, leading to rebellion against the monarchy in France and American rebellion against the British monarchy and control.
Individualism in the sense of the rights of each person, be it freedom of speech, religion, voting (for men initially) etc. It also extended to economics and private enterprise and ownership of capital in principle, if not exactly by law (outside of property rights and contracts).