The active life is to give bread to the hungry, to teach the ignorant the words of wisdom.
 Thomas Aquinas, Summa Theologica (1274). copy citation

add
Author Thomas Aquinas
Source Summa Theologica
Topic wisdom life
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/18755/pg18755-images.html

Context

“Now prayer, even when one prays for another, belongs to the contemplative life. Therefore it would seem that it belongs also to the contemplative life to acquaint another, by teaching him, of the truth we have meditated. On the contrary, Gregory says (Hom. xiv in Ezech.) : "The active life is to give bread to the hungry, to teach the ignorant the words of wisdom." I answer that, The act of teaching has a twofold object. For teaching is conveyed by speech, and speech is the audible sign of the interior concept. Accordingly one object of teaching is the matter or object of the interior concept;” source