John Chrysostom, on 1Cor 1:31

For this cause also he had vehemently inveighed against the wisdom of the Greeks, to teach men this lesson, and no other: that (as indeed is no more than just) they should boast themselves in the Lord. For when of ourselves we seek the things which are above us, nothing is more foolish, nothing weaker than we are. In such case, a tongue well whetted we may have; but stability of doctrine we cannot have. Rather, reasonings, being alone, are like the webs of spider. For unto such a point of madness have some advanced as to say that there is nothing real in the whole of being: yea, they maintain positively that all things are contrary to what appears.

Say not therefore that anything is from thyself, but in all things glory in God. Impute unto no man anything at any time. For if unto Paul nothing ought to be imputed much less unto any others. For, saith he, "I planted, Apollos watered, but God gave the increase." He that hath learnt to make his boast in the Lord, will never be elated, but will be moderate at all times, and thankful under all circumstances. But not such is the mind of the Greeks; they refer all to themselves; wherefore even of men they make gods. In so great shame hath desperate arrogance plunged them.