And he only succeeded in sounding insincere

From A Mind to Murder by P.D. James, published in 1963.  Describing a social situation where words are necessary but impossible to mould to the needs of the moment.

The pathetic thing about it, thought Baguley, was that Etherege was sincere. He meant every word. He had—and so had they all, come to that—a genuine horror of violence. He was a compassionate man shocked and saddened by the thought of a defenceless woman brutally done to death. But his words sounded false. He was taking refuge in formality, deliberately trying to lower the emotional tone of the meeting to one of platitudinous convention. And he only succeeded in sounding insincere.