In Palladius’ Lausiac History we read this story:
[1] THERE was a man named Valens, a Palestinian by race, but Corinthian in his character—-for St. Paul attributed the vice of presumption to the Corinthians. Having taken to the desert he dwelt with us for a number of years. He reached such a pitch of arrogance that he was deceived by demons. For by deceiving him little by little they induced him to be very proud, supposing that angels met him. [2] One day at least, so they told the tale, as he was working in the dark he let drop the needle with which he was stitching the basket. And when he did not find it, the demon made a lamp, and he found the needle. Again, puffed up at this, he waxed proud and in fact was so greatly puffed up that he despised the communion of the mysteries. Now it happened that certain strangers came and brought sweetmeats to the Church for the brethren. [3] So the holy Macarius our priest received them and sent a handful or so to each of us in his cell, among the rest also to Valens. When Valens received the bearer he insulted |105 him and struck him and said to him: “Go and tell Macarius, ‘I am not worse than you, that you should send me a blessing.’ ” 179 So Macarius, knowing that he was the victim of illusion, went the next day to exhort him and said to him: “Valens, you are the victim of illusions. Stop it.” And when he would not listen to his exhortations, he retired. [4] So the demon, convinced that he was completely persuaded by his deception, went away and disguised himself as the Saviour, and came by night in a vision of a thousand angels bearing lamps and a fiery wheel, in which it seemed that the Saviour appeared, and one came in front of the others and said: “Christ has loved you because of your conduct and the freedom of your life, and He has come to see you. So go out of the cell, do nothing else but look at his face from afar, stoop down and worship, and then go to your cell.” [5] So he went out and saw them in ranks carrying lamps, and antichrist about a stade away, and he fell down and worshipped. Then the next day again he became so mad that he entered into the church and before the assembled brotherhood said: “I have no need of Communion, for I have seen Christ to-day.” Then the fathers bound him and put him in irons for a year and so cured him, destroying his pride by their prayers and indifference and calmer mode of life. As it is said, “Diseases are cured by their opposites.”
Chapter XXV, trans. W.K. Lowther Clarke
In the Historia Monachorum in Aegypto — translated as The Lives of the Desert Fathers by Norman Russell in Cistercian — we also meet a monk named John whom a demon tempts by appearing in the likeness of a priest offering the Eucharist, but John sees through the deception. Moving from the fourth century to the sixth, John of Ephesus’ Lives of Eastern Saints includes the story of a monk who is deceived into venerating a prostitute because the demons doll her up and perform miracles with her, so the monk thinks she is the Blessed Virgin Mary.
All three of these stories are examples of what one may call fantasy, or fantasia (phantasia). If you, like me, are a reader of The Philokalia, you will recognise the term immediately. Fantasy, in philokalic terms, is the arising (or even calling) to mind of images at prayer. Perhaps they come from within. Perhaps from without. Perhaps one may even be perceiving the world of Platonic forms! But who knows? There is every likelihood that they are fallen and from within or demonic, evil, from without. Therefore, philokalic spirituality eschews the ascetic using his imagination at prayer.
In vol. 1 of The Philokalia, Evagrius writes:
When you are praying, do not shape within yourself any image of the Deity, and do not let your intellect be stamped with the impress of any form; but approach the Immaterial in an immaterial manner, and then you will understand.
Be on your guard against the tricks of the demons. While you are praying purely and calmly, sometimes they suddenly bring before you some strange and alien form, making you imagine in your conceit that the Deity is there. They are trying to persuade you that the object suddenly disclosed to you is the Deity, whereas the Deity does not possess quantity and form.
Evagrius the Solitary (Ponticus), Chapters on Prayer, 67-68, in Philokalia, Vol. 1, p. 63
Imageless prayer is the call of the day from The Philokalia so as not to end up like Valens and so as to resist the devil like John. Part of this concern could also be framed in the dangers of what Thomas Merton, in The Inner Experience, calls “illuminism” — that seeking after special experiences so common to some within the “mystical” and “charismatic” communities alike. The danger is that you may get the experience you are seeking — but, as Evagrius notes in ch. 73 of the Chapters on Prayer, that may well come from the demons. And their purpose is to distract you from God himself.
The result of this is that you become a Valens.
Seek God in the silence of imageless prayer, repeating the simple prayer of the neptic fathers:
Lord Jesus Christ, Son of God, have mercy on me, a sinner.