Metaphysics
What is real?
Is the physical world more or less real than the spiritual or psychological world?
Is there such a thing as a soul? And if so, how does it survive outside of a physical body?
Do all people have free will, or are lives determined by fate?
Epistemology:
How is anything known?
What is the basis for knowledge? Is it innate reason, experience, or something else?
Is all knowledge subjective, or are there some universal truths?
What is the relationship between faith and reason?
What can artificial intelligence teach people about knowledge?
What are the limits of human understanding?
Ethics:
What is the right thing to do?
What does it mean to be a good person?
Does virtue lead to happiness?
Do the ends justify the means, or is a virtuous action virtuous in and of itself?
How does living in a society affect morality?
Is morality culturally based, individually based, or is there a universal morality?
Aesthetics:
What is beautiful?
Is beauty truly in the eye of the beholder, or are there some things that all cultures find beautiful?
What is the purpose of art?
How can a piece of art be successful or valuable? Does beauty matter?
Political philosophy:
What is the best kind of government?
How much power should the government have?
What kind of people should be in power?
How involved should the common citizen be in government?
Social philosophy:
How should humans behave in a society?
Do people give up certain rights when they choose to live in a society?
How do social values affect individual beliefs? Do people behave differently in a crowd than they would individually?
How does society affect language and other types of communication?