Full Idea
The role of the wise person is to meditate on the truth, especially the truth regarding the first principle, and to discuss it with others, but also to fight against the falsity that is its contrary.
Gist of Idea
Wise people should contemplate and discuss the truth, and fight against falsehood
Source
Thomas Aquinas (Summa Contra Gentiles [1268], I.1.6), quoted by Kretzmann/Stump - Aquinas, Thomas 14
Book Reference
'Shorter Routledge Encyclopaedia of Philosophy', ed/tr. Craig,Edward [Routledge 2005], p.45
A Reaction
So nice to hear someone (from no matter how long ago) saying that wisdom is concerned with truth. If you lose your grip on truth (which many thinkers seem to have done) you must also abandon wisdom. Then fools rule.