Philosophical theories are frameworks that help us understand fundamental questions about existence, knowledge, and morality. They explore ideas like what it means to be human, the nature of reality, and how we should live our lives. Notable philosophers, such as Socrates and Immanuel Kant, have contributed to these theories, shaping our understanding of ethics and reason. Different philosophical theories can be categorized into branches like metaphysics, which studies the nature of reality, and epistemology, which examines the nature of knowledge. Each theory offers unique perspectives, encouraging us to think critically about our beliefs and the world around us.