He advocated questioning everything through the Socratic method, laying the base for critical thinking. 

He believed in an ideal world of perfect forms beyond our physical reality, influencing metaphysics and ethics. 

Philosopher Aristotle taught that virtue lies in balance, shaping ethics, science, and politics for centuries. 

Confucius focused on respect, family values, and righteousness, deeply influencing East Asian cultures. 

René Descartes laid the groundwork for modern rationalism, emphasizing doubt as a path to knowledge. 

He proposed that moral actions are guided by duty and universal principles, shaping modern ethics. 

He critiqued capitalism and introduced Marxism, influencing socio-political movements worldwide. 

He challenged traditional morality and introduced the concept of the Übermensch (Superman). 

He advocated for personal responsibility, arguing that humans create their own meaning in life. 

J. Krishnamurti encouraged individuals to break free from societal conditioning and seek truth within.