Fundamental CHARACTER is an important concept in philosophy, referring to the underlying values and beliefs that shape a person's CHARACTER. ETHOS is a Greek term meaning 'CHARACTER' or 'CUSTOM, ' and is used to refer to the moral principles and values that guide a person's behavior. ETHOS is one of the three main components of fundamental CHARACTER, along with pathos (emotion) and logos (logic). Together, these three components form the basis of a person's moral code and help to define their identity.