The Institutes, Book 9
Where Dejection Comes From
Sometimes dejection is found to come from the fault of anger that went before, or to spring from the desire for some gain that has not come about, when a man finds he has failed in his hope of getting the things he had planned. But sometimes, without any apparent reason driving us to fall into this misfortune, we are suddenly brought low, at the prompting of our crafty enemy, by so great a gloom that we cannot receive with ordinary courtesy the visits of those who are near and dear to us. Whatever subject of conversation they start, we regard as ill-timed and out of place, and we can give them no civil answer, since the gall of bitterness has taken possession of every corner of our heart.