Of all passions two are especially cruel and grievous: lust [willfulness] and despondency…when they take possession of the soul and weaken it. The two are closely connected and blended together; this is why it is so difficult to struggle with them and overcome them… The second [despondency], gripping the mind…spreads like ivy over the whole soul and body and makes our whole being lazy and enfeebled, as though stricken with paralysis.
–Writings from the Philokalia on Prayer of the Heart, p. 61, St. Gregory of Sinai
(trans. by E. Kadloubovsky and G. E. H. Palmer)