[4] This consideration is urged by De Quincey in one of his essays.
[5] iii. 1039, etc.
[6] iv. 33-38:—
Atque eadem nobis vigilantibus obvia mentes
Terrificant atque in somnis, cum saepe figuras
Contuimur miras simulacraque luce carentum,
Quae nos horrifice languentis saepe sopore
Excierunt, ne forte animas Acherunte reamur
Effugere aut umbras inter vivos volitare.
[7] An article in the Fortnightly Review of September, 1878, on 'Hallucination of the Senses,' suggests a possible explanation of the mental condition of Lucretius, during the composition of some part of his work. The writer speaks of the power of calling these hallucinations up as being quite consistent with perfect sanity of mind, but as sometimes inducing madness. He goes on, 'Or, if the person does not go out of his mind, he may be so distressed by the persistence of the apparition which he has created, as to fall into melancholy and despair, and even to commit suicide.'