Seneca used this story to illustrate the moral problem of awareness of vice. This early description of the phenomenon of unawareness of blindness was later mentioned by Michel de Montaigne (Essays, II, XXV), in a chapter primarily concerned with malingering (see discussions by Bisiach & Geminiani, 1991; Critchley, 1953, pp. 256-259). It was only in 1885, however, nearly 2000 years after Seneca’s observation, that Constantin von Monakow (professor of neurology at the University of Zürich, Switzerland) reported an association between unawareness of disease and cerebral damage, also
drawing attention to the restricted character of the responsible lesion. Von Monakow described a patient with cortical blindness and word deafness who did not see obstacles in front of him, was unable to ﬁnd the food when he had to eat, did not blink when a ﬁst was shown in front of his eyes, and looked as a blind man. His right pupil showed a reaction to light. The patient, however, did not seem to be aware of his deﬁcit. As Harpastes, he thought that the environment was dark.