If you try to save wisdom until the world is wise, Father, the world will never have it.

But neither infinite power nor infinite wisdom could bestow godhood upon men. For that there would have to be infinite love as well.

Dzieje kultury wykazują, ze głupota jest siostrą bliźniaczą rozumu, ona rośnie najbujniej nie na glebie dziewiczej ignorancji , lecz na gruncie uprawnym siódmym potem doktorów i profesorów. Wielkie absurdy nie są wymyślane przez tych, których rozum krząta się wokół spraw codziennych. Nic dziwnego zatem, że właśnie najintensywniejsi myśliciele bywali producentami największego głupstwa. / The history of culture shows that foolishness is a twin sister of wisdom. It does not flourish on the fields of pure ignorance but on the fields tirelessly plowed by doctors and professors. Great absurdities do not flourish where one is busy with everyday life. No wonder that sometimes most vigorous thinkers come up with utmost stupidities. (Dziennik 1956, XIX, Thursday)

Our wisdom comes from our experience,
and our experience comes from our foolishness.

He's acting as foolish as a kitten... but then, everyone's entitled to a little foolishness once in a while.

Those who possess wisdom cannot just ladle it out to every wantwit and jackanapes who comes along and asks for it. A person must be prepared to receive wisdom, or else it will do him more harm than good. Moreover, a lout thrashing about in the clear waters of wisdom will dirty those waters for everyone else.