The Four Troubles

Residuum erucae comedit locusta, et residuum locustae comedit bruchus, et residuum bruchi comedit rubigo.   Quator esse perturbationes, quibus animarum sanitas subvertatur, omnes philosophorum scholae conclamant. Duae praesentes sibique contrariae, duae futurae mutuo dissidentes. Praesentes, aegritudo et gaudium. Aegritudinem animi dicimus, alioquin corporis non aegritudo, sed aegrotatio nominatur. Aut igitur tristes sumus, et moerore conficimur, statusque nostrae mentis evertitur: unde at Apostolus monet, ne abundantiori tristitia absordbeatur frater. Aut econtrario gaudemus, gestimusque laetitia, et bona nostra moderantur ferre non possumus; justique et fortis viri est, nec adversis frangi, nec prosperis sublevari, sed in utroque esse moderatum. Diximus de perturbatione praesentium; dicamus et de futurorum, in quibus metus, aut spes est. Adversa timemus, prospera praestolamur; et quod aegritudo et gaudium operantur in praesenti, metus et spes faciunt de futuro, dum aut adversa plus quam decet timemus esse ventura, aut prospera quae speramus intantum nos faciunt exsultare, ut non teneamus modum, maxime in his quae incerta sunt, quia futura sperantur potius quam tenentur. Has perturbationes uno et nec pleno versiculo illustris poeta comprehendit. Hi metuunt cupiunt, dolent gaudentque neque auras, Respiciunt, clausi tenebris et carcere caeco Qui enim perturbationum tenebris obvolvuntur, clarum sapientiae lumen non valent intueri. Cavendum est igitur ne aegritudo, quasi eruca, nos comedat; ne locusta vastet in gaudio, huc illucque volitans, et gestiente laetitia, per diversa se jactans: ne bruchus, id est, pavor et futurorum metus, radices sapientiae devoret, ne rubigo et desiderium futurorum res inutiles concupiscat, et nos perferat ad ruinam. Sanctus Hieronymous, Commentarium in Joelem Prophetam, Caput I Source: Migne PL 25.952b-953a

What the worm leaves the locust eats, and what the locust leaves the swarm eats, and what the swarm leaves the blight devours. 1 All the schools of philosophy declare that there are four troubles by which the health of the soul is overthrown. Two are adversities of the present and two are disturbances regarding the future. The ones of the present are grief and joy. And we speak of the griefs of the soul, and not a discomfort of the body when we speak of grief. Either, then, we are sorrowful and consumed by woe and our firmness of mind is overturned, about which the Apostle warns us: lest an abundance of grief overwhelm our brother; 2 or on the contrary, we are joyous and we exult in our joy and we are hardly able to be moderate regarding our goods. It is of the just and virtuous man neither to be crushed by adversity nor puffed up in prosperity, but in both to exercise moderation. Thus we have spoken about the troubles of the present, and so let us now speak of the future, concerning which there is fear and hope. We are worried by adverse things and wish for prosperity, and what grief and joy do in the present, fear and hope do regarding the future, that either we fear coming adversities more than we should, or the mere hope of prosperity makes us exult, something which we have yet to acquire, in which there is great uncertainty, because future things are hoped for rather than possessed. These troubles the famous poet in a few verses understands: These things they fear desiring, and lament rejoicing,  Seeing not the skies, shut in darkness and in prison blind. 3 For he who is overturned by troubles is in darkness, unable to see with the clear light of wisdom. Let us be wary, then, that neither grief, like the worm, consumes us, nor the locust lays waste to us with joy, for this and that one flittering about us, even when it bears joy, may cast us down by various means. Nor let the swarm, that is, fear and distress regarding the future, devour the roots of wisdom, nor the blight fill us with desires for worthless things in the future, and so bear us off to ruin. Saint Jerome, Commentary on The Prophet Joel, Chapter 1 1 Joel 1.4 2 2 Cor 2.7 3 Aeneid 6.733-4