Often in our sleep we see, or we believe we see, what has struck our attention very much when awake; sometimes we represent to ourselves in sleep things of which we have never thought, which even are repugnant to us, and which present themselves to our mind in spite of ourselves. None bethink themselves of seeking the causes of these kinds of representations; they are attributed to chance, or to some disposition of the humors of the blood or of the brain, or even of the way in which the body is placed in bed; but nothing like that is applicable to the apparitions of angels, demons, or spirits, when these apparitions are accompanied and followed by converse, predictions and real effects preceded and predicted by those which appear. If we have recourse to a pretended fascination of the eyes or the other senses, which sometimes make us believe that we see and hear what we do not, or that we neither see nor hear what is passing before our eyes, or which strikes our ears; as when the soldiers sent to arrest Elisha spoke to him and saw him before they recognized him, or when the inhabitants of Sodom could not discover Lot's door, although it was before their eyes, or when the disciples of Emmaus knew not that it was Jesus Christ who accompanied them and expounded the Scriptures; they opened their eyes and knew him _only by the breaking of bread_. That fascination of the senses which makes us believe that we see what we do not see, or that suspension of the exercise and natural functions of our senses which prevents us from seeing and recognizing what is passing before our eyes, is all of it hardly less miraculous than to condense the air, or rarefy it, or give solidity and consistence to what is purely spiritual and disengaged from matter. From all this, it follows that no apparition can take place without a sort of miracle, and without a concurrence, both extraordinary and supernatural, of the power of God who commands, or causes, or permits an angel, or a demon, or a disembodied soul to appear, act, speak, walk, and perform other functions which belong only to an organized body. I shall be told that it is useless to recur to the miraculous and the supernatural, if we have acknowledged in spiritual substances a natural power of showing themselves, whether by condensing the air, or by producing a massive and palpable body, or in raising up some dead body, to which these spirits give life and motion for a certain time.