"Filhyn smiled. “Is it not always better to tell the truth though, Representative?” Errun looked at her, shook his head. “The truth? No matter what? For good or ill? Are you mad? I do hope you’re having a joke with me here, young lady….Don’t pretend you are so naive, Filhyn. The truth is not always useful, not always good. It’s like putting your faith in water. Yes, we need the rain, but too much can sweep you away in a flood and drown you. Like all great natural, elemental forces, the truth needs to be channelled, managed, controlled and intelligently, morally allocated.” He glared at her. “You are having a joke with me, aren’t you?” I might as well be, she thought. She wondered if she would finally be a real politician when she agreed with what Errun was saying."
January 1, 1970
https://en.wikiquote.org/wiki/Iain_Banks