By the second class of causes, which have been termed _moral_, are meant those which are supposed to originate in the mind, or which are more immediately applied to it. Such are, the long endurance of grief; ardent and ungratified desires; religious terror; the disappointment of pride; sudden fright; fits of anger; prosperity humbled by misfortunes:[15] in short, the frequent and uncurbed indulgence of any passion or emotion, and any sudden or violent affection of the mind. There are, doubtless, many other causes of both classes, which may tend to produce this disease. Those which have been stated, are such as I am most familiar with; or, to speak more accurately, such are the circumstances most generally found to have preceded this affection. It is an old opinion, and continues still to prevail, that maniacs are influenced by the changes of the moon. In the fourth chapter of St. Matthew's Gospel, verse 24, we find the word "[Greek: Seleniaxomenous]" which is rendered in the English version, "those which were lunatic." Notwithstanding the notion of being moon-struck might prevail among the ignorant people of Galilee, yet Hippocrates, a philosopher, and correct observer of natural phaenomena, does not appear to have placed any faith in this planetary influence. Although the Romans were infected with this popular tradition, as may be seen in the following passage of the Art of Poetry, "Ut mala quem scabies aut morbus regius urget, Aut fanaticus error, et IRACUNDA DIANA Vesanum tetigisse timent fugiuntque poetam, Qui sapiunt:"-- yet Celsus did not consider the operation of the moon on the human intellect sufficiently well founded to admit it into his medical work. Not a word on this subject is mentioned in the eighteenth chapter of his third book, which particularly treats of Insanity, "_De tribus insaniae generibus_;" it is true that, in the fourth chapter of the first book, which speaks "_De his quibus caput infirmum est_," he says "Cui caput infirmum est, is si bene concoxit, leniter perfricare id mane manibus suis debet; nunquam id, si fieri potest, veste velare; aut ad cutem tondere: utileque lunam vitare, maximeque ante ipsum lunae solisque concursum." By the _infirmum caput_, Celsus does not mean madness, as may be clearly seen by perusing the chapter: the weakness of intellect, which frequently continues after fever, or other violent diseases, is evidently his meaning; but Dr. Cox has quoted the above passage, to prove that Celsus was impressed with the truth of this vulgar opinion. He says, "This idea of lunar influence, in _maniacal complaints_, was handed down to us by our medical forefathers, and is still very generally adopted."