Q. Are the passions evil in themselves or do they become so when used in an evil way? I am speaking of pleasure, grief, desire, fear, and the rest.
R. These passions, and the rest as well, were not originally created together with human nature, for if they had been they would contribute to the definition of human nature. But following what the eminent Gregory of Nyssa taught, I say that, on account of humanity’s fall from perfection, the passions were introduced and attached themselves to the more irrational part of human nature. Then, immediately after humanity had sinned, the divine and blessed image was displaced by the clear and obvious likeness to unreasoning animals. The passions, moreover, become good in those who are spiritually earnest once they have wisely separated them from corporeal objects and used them to gain possession of heavenly things. For instance, they can turn desire (ἐπιθυμία) into the appetitive movement of the mind’s longing for divine things, or pleasure (ἡδονή) into the unadulterated joy of the mind when enticed toward divine gifts, or fear (φόβος) into cautious concern for imminent punishment for sins committed, or grief (λύπη) into corrective repentance of a present evil.
From Maximus the Confessor in Ad Thalassium (On the Utility of the Passions1, ccsg 7: 47–49).
When we wish to give a collective name to the passions, we call them world. And when we wish to designate them specifically according to their names, we call them passions. The passions are portions of the course of the world’s onward flow; and where the passions cease, there the world’s onward flow stands still.
From The Ascetical Homilies of Saint Isaac the Syrian (Homily Two, trans. by the Holy Transfiguration Monastery, Boston, 1984, p. 14).
If neither the Deity is passible nor our nature free from passion, what other account remains whereby we may say that the word of God speaks truly, which says that man was made in the image of God? [XVI.4]
It is not allowable to ascribe the first beginnings of our constitutional liability to passion to that human nature which was fashioned in the Divine likeness; but as brute life first entered into the world, and man, for the reason already mentioned, took something of their nature (I mean the mode of generation), he accordingly took at the same time a share of the other attributes contemplated in that nature. [XVIII.1]
Thus our love of pleasure took its beginning from our being made like to the irrational creation, and was increased by the transgressions of men, becoming the parent of so many varieties of sins arising from pleasure as we cannot find among the irrational animals. Thus the rising of anger in us is indeed akin to the impulse of the brutes; but it grows by the alliance of thought: for thence come malignity, envy, deceit, conspiracy, hypocrisy; all these are the result of the evil husbandry of the mind; for if the passion were divested of the aid it receives from thought, the anger that is left behind is short-lived and not sustained, like a bubble, perishing straightway as soon as it comes into being. Thus the greediness of swine introduces covetousness, and the high spirit of the horse becomes the origin of pride; and all the particular forms that proceed from the want of reason in brute nature become vice by the evil use of the mind. [XVIII.4]
So, likewise, on the contrary, if reason instead assumes sway over such emotions, each of them is transmuted to a form of virtue; for anger produces courage, terror caution, fear obedience, hatred aversion from vice, the power of love the desire for what is truly beautiful; high spirit in our character raises our thought above the passions, and keeps it from bondage to what is base; yea, the great Apostle, even, praises such a form of mental elevation when he bids us constantly to think those things that are above (Colossians 3:2); and so we find that every such motion, when elevated by loftiness of mind, is conformed to the beauty of the Divine image. [XVIII.4]
The misery that encompasses us often causes the Divine gift to be forgotten, and spreads the passions of the flesh, like some ugly mask, over the beauty of the image. [XVIII.6]
Passion in the human soul is a conformity to the likeness of the irrational. [XXVIII.4]
From On the Making of Man by Gregory of Nyssa.