John Chrysostom

"When I therefore was thus minded, did I show fickleness?" Here in what follows, he directly does away with the charge arising out of his delay and absence. For what he says is of this nature. "I was minded to come unto you." "Wherefore then did I not come? Is it as light-minded and changeable?" for this is, "did I show fickleness?" By no means. But wherefore? …

Homily 3 on 2 Corinthians ↗

Theophylact of Ohrid

Here he more clearly defends himself regarding the delay, saying that he wished to come to them, but why did he not come? Is it because I am fickle and inconstant, deciding now one way, now another? No. Or do I desire according to the flesh, that is, in a human manner, and am guided by my own will, so that whatever I decide myself, I carry out, whether it be yes or no? Not at all. But I am under the direction of the Spirit and do not have the authority to go where I wish, but where He commands. …

Commentary on 2 Corinthians ↗

Thomas Aquinas

Then he puts the accusation for this change, for which the Corinthians accused him, in the form of a question, saying, Was I vacillating when I wanted to do this? For on account of this they charged him with two things: light-mindedness, because he changed his mind: "The fool changes like the moon" (Sir. 27:11); and carnal love, because it seemed to them that he had done this from some carnal and human affection. …

Commentary on 2 Corinthians ↗