Most of us at some point in our lives ask questions such as: What makes an action right or wrong? What is the meaning of life? How should I live? Does God exist? How can we distinguish knowledge from opinion? Is the mind the same as the brain? What is required for a society to be just? Do human beings have freedom of the will? Life confronts every thoughtful person with some philosophical questions, and nearly everyone is guided by philosophical assumptions that make up their world view, although often these assumptions are held unconsciously. In order to become aware of these assumptions and to think clearly about them, we need to approach them skillfully and systematically. Philosophy is the practice of developing the skills and strategies for answering fundamental questions about human existence. Philosophy classes offer a unique opportunity to address such permanent questions and consider the most impressive answers that people throughout the history of thought have produced.
Philosophers use reasoned argument to evaluate beliefs, focusing especially on what evidence there is for a belief, whether it fits well with other beliefs or contradicts them, and whether we can prove it or disprove it. Although philosophy has a subject matter of its own-the beliefs that form our world views- its range is extensive and often involves reflection on the subject matter of other disciplines. For example, philosophy of mind addresses issues in psychology; philosophy of science addresses issues in biology, physics, and the social sciences, aesthetics is concerned with art and music, and ethics and political philosophy address issues in political science, women's studies, and legal studies.
The philosopher Wilfred Sellars has perhaps the best summary of what philosophy is:
"The aim of philosophy... is to understand how things in the broadest possible sense of the term hang together in the broadest possible sense of the term. Things... include... not only 'cabbages and kings', but numbers and duties, possibilities and finger snaps, aesthetic experience and death. To achieve success in philosophy would be... to know one's way around with respect to all these things, not in that unreflective way in which the centipede of the story knew its way around before it raised the question 'how do I walk?', but in that reflective way which means that no intellectual holds are barred."