Answer:
Step-by-step explanation:
There could be any number of answers to this question, since you are allowed to choose on the basic of what you studied. I'll suggest a couple of prominent examples here, but you should pick what stood out to you from your studies.
In political philosophy, theories on the origins of governmental authority and the structure of governments, as developed by thinkers like Locke, Montesquieu, Voltaire, and Rousseau have had a huge impact on historical developments that followed, contributing to the American Revolution (esp. Locke and Montesquieu) and the French Revolution (also Voltaire and Rousseau).
In ethics, the categorical imperative approach of Immanuel Kant continues to have strong influence on ethical thinking today. Kant stressed that we need to treat all other rational beings not as means to an end for ourselves, but as ends in themselves, equal to ourselves. He urged that all actions need to be such that they would be sensible if applied universally to all persons.