From the first volume of The Philokalia:
Our sixth struggle is against the demon of listlessness, who works hand in hand with the demon of dejection. This is a harsh, terrible demon, always attacking the monk, falling upon him at the sixth hour (mid-day), making him slack ad full of fear, inspiring him with hatred for his monastery, his fellow monks, for work of any kind, and even for the reading of Holy Scripture. He suggests to the monk that he should go elsewhere and that, if he does not, all his effort and time will be wasted. In addition to all this, he produces in him at around the sixth hour a hunger such as he would not normally have after fasting for three days, or after a long journey or the heaviest labor. Then he makes him think that he will not be able to rid himself of this grievous sickness, except by sallying forth frequently to visit his brethren, ostensibly to help them and to tend to them if they are unwell. When he cannot lead him astray in this manner, he puts him into the deepest sleep. In short, his attacks become stronger and more violent, and he cannot be beaten off except through prayer, through avoiding useless speech, through the study of the Holy Scriptures and through patience in the face of temptation. If he finds a monk unprotected by these weapons, he strikes him down with his arrows, making him a wayward and lazy wanderer, who roams idly from monastery to monastery, thinking only of where he can get something to eat and drink. The mind of someone affected by listlessness is filled with nothing but vain distraction. Finally he is ensnared in worldly things and gradually becomes so grievously caught up in them that he abandons the monastic life altogether.The Apostle, who knows that this sickness is indeed serious, and wishes to eradicate it from our soul, indicates its main causes and says: "Now we command you, brethren, in the name of our Lord Jesus Christ, to withdraw yourselves from every brother who lives in an unruly manner and not according to the tradition which you have received from us. For you yourselves know how you ought to initiate us for we ourselves did not behave in an unruly manner when among you, nor did we eat any man's bread as a free gift; but we toiled strenuously night and day so that we might not be a burden to any of you: not because we do not have the right, but so as to give you an example to imitate. For even when we were with you, we have you instructions that if anyone refuses to work he should have nothing to eat. For we hear that there are some among you who love in an unruly manner, nor working at all, but simply being busybodies. Now we instruct such people and exhort them by our Lord Jesus Christ to work quietly and to eat their own bread (2 Thess. 3:6-12). We should note how clearly the Apostle describes the causes of listlessness. Those who do not work he calls unruly, expressing a multiplicity of faults in this one word. For the unruly man is lacking in reverence, impulsive in speech, quick to abuse, and so unfit for stillness. He is a slave to listlessness. Paul therefore tell us to avoid such a person, that is, to isolate ourselves from him as from a plague. With the words "and not according to the traditions which you have received from us" he makes it clear that they are arrogant and that they destroy the apostolic traditions. Again he says: "nor did we eat any man's bread as a free gift; but we toiled strenuously night and day." The teacher of the nations, the herald of the Gospel, who was raised to the third heaven, who says that the Lord ordained that "those who preach the Gospel should live by the Gospel" (I Cor 9:14) – this same man works night and day "so that we might not be a burden to any of you." What then can be said of us, who are listless about our work and physically lazy – we who have not been entrusted with the proclamation of the Gospel or the care of the churches, but merely with looking after our own soul? Next Paul shows more clearly the harm born of laziness by adding: "not working at all, but simply being busybodies"; for from laziness comes inquisitiveness, and from inquisitiveness, unruliness, and from unruliness, every kind of evil. He provides a remedy, however, with the words: "Now we instruct such people... to work quietly and to eat their own bread." But with even emphasis, he says: "if anyone refuses to work, he should have nothing to eat."The holy fathers of Egypt, who were brought up on the basis of these apostolic commandments, do not allow monks to be without work at any time, especially when they are young. They know that by persevering in work monks dispel listlessness, provide for their our sustenance and help those who are in need. They not only work for their own requirements, but from their labor they also minister to their guests, to the poor and to those in prison, believing that such charity is a holy sacrifice acceptable to God. The fathers also say that as a rule someone who works is attacked and afflicted by but a single demon, while someone who does not work is taken prisoner by a thousand evil spirits.It is also good to recall when Abba Moses, one of the most experienced of the fathers, told me. I had not been living long in the desert when I was troubled by listlessness. So I went to him and said: "Yesterday I was greatly troubled and weakened by listlessness, and I was not able to free myself from it until I went to see Abba Paul." Abba Moses replied to me by saying: "So far from freeing yourself from it, you have surrendered to it completely and become its slave. You must realize that it will attack all the more severely because you have deserted your post, unless from now on you strive to subdue it through patience, prayer and manual labor."