Philosophy provides the foundation for educational philosophy. Educational philosophy helps educators interpret and direct their work in the classroom. There are several branches and elements of philosophy that influence education, including epistemology, which examines how knowledge is acquired, metaphysics which examines the nature of reality, and axiology which examines values and ethics. Educational philosophies aim to transmit cultural heritage, transform culture, and maximize human potential, and include perennialism, essentialism, behaviorism, progressivism, existentialism, reconstructivism, postmodernism, and social reconstructionism.