An Athenian philosopher who led dialogues through the Socratic method, exploring morality and wisdom. He emphasized intellectual humility and ethical reflection, laying the foundation for Western philosophy.

Advocated the Theory of Forms and proposed the ideal state and the tripartite theory of the soul. He founded the Academy to mentor disciples and left a massive footprint on Western thought through metaphysics and political philosophy.

An empirical philosopher who valued observation and experience, creating a broad system of knowledge including logic, ethics, and natural science. He deeply influenced medieval Scholasticism and the development of modern science.

The founder of Confucianism, he emphasized moral humanity and social order through Ren (benevolence) and Li (ritual). He exerted a decisive influence on East Asian culture, politics, and education while preaching a moral life.

The fundamental thinker of Taoism, he spoke of Wu Wei (non-action) and a simple life, remaining skeptical of artificial norms and authority. He valued personal freedom and inner peace through harmony with nature.

Sought certainty through methodical doubt and established the foundation of modern philosophy with "I think, therefore I am." He highlighted the importance of rationality and the scientific method, contributing greatly to modern philosophy and mathematics.

Reconstructed the relationship between reason and experience, emphasizing universal moral laws and subjective autonomy through the Categorical Imperative. A turning point in modern philosophy and a core of Enlightenment thought.

Critiqued existing morality and religion, urging the creation of new values through the Will to Power and the concept of the Übermensch. His stylistic experimentation and critical thinking caused a major stir in modern philosophy, literature, and psychology.

Explained the development of history and spirit through dialectics, integrating the state, art, and religion into a holistic philosophical system. He exerted a powerful influence on European intellectual history through his philosophy of history.

Analyzed the structure of capitalism and class struggle to present historical materialism, laying the groundwork for theories of social transformation. A thinker who integrated political, economic, and social theory to influence modern social movements.