“A lawyer should seek the truth”

Mason shook his head.
“Why not?” Drake asked.
“Because,” Mason said, “it isn’t the truth.”
“Don’t be naive,” Drake said. “A lot of criminal lawyers I know don’t pay much attention to the truth. Often when the truth would get a client stuck a good lawyer has to resort to something else.”
“I’m afraid of anything that isn’t the truth.” Mason said. “My client tells me a story that’s almost impossible to believe, but it’s her story. If I, as her attorney, adhere to that story I at least am being true to the ideals of my profession. I may think it’s a lie, but I don’t know it’s a lie.
“If, however, I think up some synthetic story, then I know it’s false and I’m afraid of anything that’s false. A lawyer should seek the truth.”
“But your client’s story, from what I gather about it, can’t be true,” Drake said.
“Then,” Mason said, “it’s up to me to seek out the truth.”

—Erle Stanley Gardner, The Case of the Glamorous Ghost