The term “existentiality” refers to human existence and to the person’s existential world in which he or she lives their freedom and responsibility. The psychiatrist Binswanger suggested that to understand another person we have to consider three existential modes of that person’s worldly existence: Umwelt (the surrounding world in which we live), Mitwelt (our shared world with others), and Eigenwelt (the self-world in which we know ourselves as who we are).