How do we define, how do we describe, how do we explain...

How do we define, how do we describe, how do we explain and/or understand ourselves? What sort of creatures do we take ourselves to be? What are we? Who are we? Why are we? How do we come to be what or who we are or take ourselves to be? How do we give an account of ourselves? How do we account for ourselves, our actions, interactions, transactions (praxis), our biologic processes? Our specific human existence?