However, this in turn led me to a quote from the american author and doctor Oliver Wendell Holmes, Sr., who with some certainty should be the author of the following:
It is the province of knowledge to speak, and it is the privilege of wisdom to listen.I think it is a beautiful quote - and so obviously true. If you carry knowledge, you have a good point from which to speak - but wisdom is achieved by listening (and reading, and in other ways absorbing knowledge).
(Translated from Noget om viden og visdom)