Calvin on suffering and prosperity

I am reading and enjoying Dr. Will Varner's new EEC volume on James. Varner quotes Calvin in a footnote on James 5:13 ("Is anyone among you suffering? Let him pray. Is anyone cheerful? Let him sing praise"), introducing it with the words, "A famous pastor-theologian, who suffered physically throughout his life, offered some sage advice from this verse, drawn from his own experience."

Here is Calvin:

He means that there is no time in which God does not invite us to himself. For afflictions ought to stimulate us to pray; prosperity supplies us with an occasion to praise God. But such is the perverseness of men, that they cannot rejoice without forgetting God, and that when afflicted they are disheartened and driven to despair. We ought, then, to keep within due bounds, so that the joy, which usually makes us to forget God, may induce us to set forth the goodness of God, and that our sorrow may teach us to pray. For he has set the singing of psalms in opposition to profane and unbridled joy; and thus they express their joy who are led, as they ought to be, by prosperity to God. [Calvin, J., & Owen, J. (2010). Commentaries on the Catholic Epistles (pp. 354–355). Bellingham, WA: Logos Bible Software.]