Sigmund Freud, a famous psychologist, used the word in one of his theories. THANATOS was the god or personified spirit ("daimon") of non-violent death. His touch was gentle, likened to that of his twin brother Hypnos(Sleep). Violent death was the domain of Thanatos' blood-craving sisters, the Keres, spirits of slaughter and disease. He is often confused with Hades, who is the god of the dead and underworld, not death itself.