Philosophical anthropology is the philosophical study of human nature. In terms of learning, examples of descriptive theories of the learner are: a mind, soul, and spirit capable of emulating the Absolute Mind (Idealism); an orderly, sensing, and rational being capable of understanding the world of things (Realism), a rational being with a soul modeled after God and who comes to know God through reason and revelation (Neo-Thomism), an evolving and active being capable of interacting with the environment (Pragmatism), a fundamentally free and individual being who is capable of being authentic through the making of and taking responsibility for choices (Existentialism). Philosophical concepts for the process of education include "Bildung" and "paideia".