Theophylact of Ohrid, on 1Cor 1:21

“For seeing that in the wisdom of God the world, by wisdom, knew not God, it pleased God, by the foolishness of our preaching, to save them that believe.”

“He gives the reason why worldly wisdom turned into foolishness. Since in the wisdom manifest in creatures (for heaven and earth and all creation proclaims the Creator: see Ps. 19:2; Rom. 1:20), "the world," that is, those who think in worldly terms, did not know God (evidently because wisdom of the kind seen in eloquence hindered it from doing so), it pleased God to save believers through the simplicity of preaching (which only seemed like foolishness but was not truly so). Thus the Greeks had as their teacher the wisdom of God, that is, the wisdom discerned in creatures, yet they did not know God, because they were guided by the wisdom that consists in eloquence, which is not true wisdom.”

Imported from an open dataset — not yet checked against the printed edition.