Dream-images of the dead are like dream-images of the living
Augustine is arguing that appearances of the dead in dreams are likenesses, not the dead person's soul, just as dreams of living people are likenesses.
Human weakness is such that when someone sees a dead person in a dream, he thinks he is seeing that person's soul; but when he dreams of a living person in the same way, he does not doubt that what appeared to him was not that person's soul or body but a likeness of the person. As if the likenesses of dead people—who likewise know nothing—could not appear to sleepers in the same way. For certain, when we were in Milan, we heard that a debt was being demanded from a man on the strength of a bond produced by his deceased father, a bond the father had already paid off without the son's knowledge. The man began to be deeply distressed and astonished that his father had not told him as he was dying what he owed, since he had even made a will. Then, in his great anxiety, his father appeared to him in a dream and showed him where the receipt was that had cancelled that bond. When the young man found it and produced it, he not only drove off the false accusation of an unpaid debt but also recovered his father's written bond, which his father had not received back when the money was paid. Here one would certainly think that the man's soul had taken care for his son and had come to him while he slept, so that by teaching him what he did not know, it might free him from great trouble. But at almost the same time that we heard this—that is, while we were staying in Milan—Eulogius, a rhetorician of Carthage who had been my student in that art, as he himself told me after we returned to Africa, was lecturing his students on Cicero's rhetorical books. While reviewing the lesson he was to give the next day, he came upon an obscure passage, and because he could not understand it he could hardly sleep for worry. That night, as he dreamed, I explained to him what he did not understand—or rather, not I, but my image, while I knew nothing of it and was far away across the sea, doing or dreaming something else and not caring at all about his concerns. How these things happen I do not know; but however they happen, why do we not believe that a person sees a dead man in dreams in the same way that he sees a living one? In both cases, surely, the people themselves neither know nor care who dreams their likenesses, or where, or when.
Latin
Sic autem infirmitas humana sese habet, ut, cum mortuum in somnis quisque uiderit, ipsius animam se uidere arbitretur, cum autem uiuum similiter somniauerit, non eius animam neque corpus, sed hominis similitudinem sibi adparuisse non dubitet. quasi non possint et mortuorum hominum eodem modo nescientium non animae, sed similitudines adparere dormientibus. pro certo, cum Mediolani essemus, audiuimus, quod cum debitum repeteretur a quodam defuncti patris cautione prolata, quod filio nesciente a patre iam fuerat persolutum, contristari homo grauissime coepit atque mirari. quod ei pater moriens non dixerit, quid deberet, cum fecisset etiam testamentum. tunc ei nimis anxio adparuit idem pater eius in somnis et ubi esset recautum, quo illa cautio uacuata fuerat, indicauit. quo inuento iuuenis atque monstrato non solum falsi debiti calumniam propulsauit, sed etiam paternum recepit chirographum, quod pater non receperat, quando est pecunia persoluta. hic utique putatur anima hominis curam gessisse pro filio et ad eum uenisse dormientem, ut docens. quod ignorabat, magna molestia liberaret. sed eodem ipso ferme tempore, quo id audiuimus, id est nobis apud Mediolanum constitutis Carthaginis rhetor Eulogius, qui meus in eadem arte discipulus fuit, sicut mihi ipse, posteaquam in Africam remeauimus, retulit, cum rhetoricos Ciceronis libros discipulis suis traderet, recensens lectionem, quam postridie fuerat traditurus, quendam locum offendit obscurum, quo non intellecto uix potuit dormire sollicitus. qua nocte somnianti ego illi quod non intellegebat exposui, immo non ego, sed imago mea nesciente me et tam longe trans mare aliquid aliud siue agente siue somniante et nihil de illius curis omnino curante. quomodo fiant ista nescio; sed quomodolibet fiant. cur non eodem modo fieri credimus, ut in somnis quisque uideat mortuum, quomodo fit, ut uideat et uiuum? ambobus utique nescientibus neque curantibus, quis uel ubi uel quando eorum imagines somniet.