“Isn't it really, really offensive that our president is simply not telling us the truth about what's happening in Iraq? For me, that was one of the most offensive things about the entire convention. There was no truth-telling there. It was all a complete masquerade. Both about Iraq and about the domestic economy… The problem is not that the people think the Democratic Party is not sufficiently hawkish; it's the problem that they are not sufficiently bold and sufficiently visionary. They need to go back to Bobby Kennedy and 1968. That was the last time that a Democrat truly inspired red states and blue states and everybody and the millions of people out there.”

Source: Red Mars

Music, Mind, and Meaning (1981)

Source: The Truth About Forever

Campaign statement in Fresno, California (10 September 1952); earlier incidence of similar comments exist:
If Mr. Hughes will stop lying about me, I will stop telling the truth about him.
William Randolph Hearst, about Charles Evans Hughes, in 1906, as quoted in The Quote Verifier : Who Said What, Where, and When (2006) by Ralph Keyes
If you will refrain from telling any lies about the Republican Party, I'lll promise not to tell the truth about the Democrats.
Chauncey Depew, as quoted in "If Elected I Promise … "Stories and Gems of Wisdom by and About Politicians (1969) by John F. Parker

"The Leaning Tower", lecture delivered to the Workers' Educational Association, Brighton (May 1940)
The Moment and Other Essays (1948)

Source: Gargantua and Pantagruel (1532–1564), Third Book (1546), Chapter 52 : How a certain kind of Pantagruelion is of that nature that the fire is not able to consume it
Context: I have already related to you great and admirable things; but, if you might be induced to adventure upon the hazard of believing some other divinity of this sacred Pantagruelion, I very willingly would tell it you. Believe it, if you will, or otherwise, believe it not, I care not which of them you do, they are both alike to me. It shall be sufficient for my purpose to have told you the truth, and the truth I will tell you.

MTV Unplugged 2.0, By: Lauryn Hill (2002)

Variant: If you can't tell the truth to the people you care about the most, eventually you stop being able to tell the truth to yourself.
Source: City of Ashes