LUNATIC (σελγνιαζόμενος, from σελήνη “moon”). - The ancients called l. those afflicted by epilepsy (falling sickness, sacred disease, comitial disease), which was attributed to lunar influences.
Among the many sick persons healed by Jesus near the lake of Tiberinde there were also l. (σελγνιαζόμενοι; Mt. 4, 24), who in this case are distinguished from the possessed (δαιμονιζόμενοι).
On the other hand, the l. healed by Jesus after the Transfiguration (v.) was also possessed. The event is narrated by the three Synoptics (Mt. 17, 15, among the symptoms of the illness, writes: σελγνιάζεται “lunaticus est”; Mc. 9, 14-29 provides fuller details; Lc. 9, 37-43 follows a middle course). That boy was not only epileptic but also possessed is evident not only from the impression of the father and the Apostles (which might reflect the common popular mentality that attributed illnesses, and especially these, to the demon) but also from the clear assertion of the Evangelists and above all from Jesus’ exorcism: “Mute and deaf spirit, I command you, come out of him and never enter him again” (Mc. 9, 25).
The symptoms of muteness and deafness and other details are not those of epilepsy. The hypothesis that Jesus accommodated himself to a false popular opinion by speaking in this manner cannot be maintained: he taught the reality of diabolical possessions and, after the miracle, added to the Apostles, distressed because they had been unable to cast out the evil spirit: “This kind cannot be driven out except by prayer [and fasting]” (Mc. 9, 29).