[S]ometimes [vainglory] creates a wish to take holy orders, and a desire for the priesthood or diaconate. And it represents that if a man has even against his will received this office, he will fulfil it with such sanctity and strictness that he will be able to set an example of saintliness even to other priests; and that he will win over many people, not only by his manner of life, but also by his teaching and preaching. It makes a man, even when alone and sitting in his cell, to go round in mind and imagination to the dwellings and monasteries of others, and to make many conversions under the inducements of imaginary exultation.
And so the miserable soul is affected by such vanity–as if it were deluded by a profound slumber–that it is often led away by the pleasure of such thoughts, and filled with such imaginations, so that it cannot even look at things present, or the brethren, while it enjoys dwelling upon these things, of which with its wandering thoughts it has waking dreams, as if they were true.
I remember an elder, when I was staying in the desert of Scete, who went to the cell of a certain brother to pay him a visit, and when he had reached the door heard him muttering inside, and stood still for a little while, wanting to know what it was that he was reading from the Bible or repeating by heart (as is customary) while he was at work. And when this most excellent eavesdropper diligently applied his ear and listened with some curiosity, he found that the man was induced by an attack of this spirit to fancy that he was delivering a stirring sermon to the people. And when the elder, as he stood still, heard him finish his discourse and return again to his office, and give out the dismissal of the catechumens, as the deacon does, then at last he knocked at the door, and the man came out, and met the elder with the customary reverence, and brought him in and (for his knowledge of what had been his thoughts made him uneasy) asked him when he had arrived, for fear lest he might have taken some harm from standing too long at the door: and the old man joking pleasantly replied, “I only got here while you were giving out the dismissal of the catechumens.” (Institutes Bk. 11. 14-16)