Of the eight principal spirits or faults, dejection and acedia most effectively link the monastic world with today’s psychological suffering. The spirit or demon of dejection is described as one that attacks at random, and prevents the monk from having gladness of heart.[32] It makes the monk impatient and rough with the brethren and causes him to feel angry, crushing and overwhelming him with despair.[33] Cassian also locates the origin of dejection as being from “previous anger” or a previous “lack of gain that has not been realized.”[34] The monk isolates himself and no longer desires to engage in discourse with others, so that Cassian labels dejection the “gall of bitterness that is in possession of every corner of their heart.”[35] Interestingly, Cassian discusses how this demonic spirit is not necessarily a result of the actions of others, but actions of the self. Cassian elaborates that one in this state should not isolate himself, but rather continue to interact with his fellow monastic brethren. This in itself is a remedy against this spirit.[36] 

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However, Cassian goes on to discuss that some dejection is acceptable and therapeutic. This is the sorrow that leads an individual to penitence for sin.[39] Finally, he ends the relevant chapter by noting that the way to terminate devilish dejection is spiritual meditation, and keeping the mind occupied with the hope of the future. In examining this chapter of Cassian’s work, clear symptoms emerge, as well as treatment modalities for what is considered depression in the modern world.

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In Book X of the Institutes, Cassian begins to describe accidie, or acedia, known as the “midday demon,”[40] as Evagrius had also done, although in more detail in specific relation to the emotions.[41] While similar to the demon of dejection, acedia consists of the added features of apathy, sluggishness, sloth, and irritability. In naming acedia the “midday demon,” Cassian posits that these demonic attacks often occur around the sixth hour and seize the monk. Carelessness and anxiousness are the main components of acedia, as well as frequent complaining.[42] The monk looks anxiously and often sighs at his other brethren. There are also moments where he is idle and useless for spiritual work. Cassian notes that sometimes the midday demon can manifest in different forms: sometimes one may isolate more, and in other times one may become a busy-body and seek consolation from others — an action which Cassian describes as entanglement in secular business.[43] 

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Cassian similarly recognized that often, anger and the lack of accomplishing a goal can lead to the demon of dejection. Anger and failure are, after all, often linked to stressful situations in an individual’s life.

John Cassian, Diabolical Warfare, and Psychological Health
Abraham Ghattas
Doss Press