All that is true, from anyone it is said, always comes from the Holy Spirit.
Omne verum a quocumque dicatur a Spiritu Sancto est.
Original text (Latin)
Notes from Wikiquote
Summa Theologiae, I-II, q. 109, a. 1, ad 1
Original text (Latin)
Charity, by which God and neighbor are loved, is the most perfect friendship.
It must be said that charity can, in no way, exist along with mortal sin.
Quote text and notes from Wikiquote: Thomas Aquinas (page history), available under CC BY-SA 4.0. Source quality and labels are our own summary of what Wikiquote records.