“While it is commendable to have love for both, we ought to honour truth as sacred above friends,” Aristotle says in the Nicomachean Ethics (106a14-17). Most people do not live this way. Instead, they mistakenly believe that a friendship can flourish based on falsehood. But it can’t, as Aquinas explains in his Commentary on Aristotle’s Nicomachean Ethics, Bk. I, Lect. VI. And this is especially important for the friendship that exists between husbands and wives.
If our friendships are based on falsehood, they aren’t really friendships at all. “Unless a man prefer truth to his friends,” Aquinas explains, “it follows that he will make false judgment and bear false witness in their defence. This is contrary to virtue.” It is contrary to not only our own virtue but also that of our friends. Making false judgments and bearing false witness enables people to live in fantasy, not reality.
Indeed, Aquinas adds, “although we should have friendship for both truth and our fellow man, we ought rather to love truth because we should love our fellow man especially on account of truth and virtue.” If your friendships are based on reality — even if it’s just the reality of your shared fortitude in having the endurance to overcome your many vices — then that’s healthy. But a love that allows lies isn’t really love at all.
Most importantly, however, 'truth is a most excellent friend of the sort to whom the homage of honour is due.’ It might seem strange to think of truth as friend, but of course God is Truth, and God is a Person. That’s why Aquinas refers to charity — the love of God for the sake of loving God — as a love of ‘friendship.’ Truth is found ‘first and chiefly in God,’ and so loving truth makes us friends of God.