“I am a rational man, but haven't you heard? i'm also insane. It gives me a unique perspective on things.”

As quoted in the London Times, July 1, 2000.

Source: The Pearl (1947), Ch. V
Context: He had said, "I am a man," and that meant certain things to Juana. It meant that he was half insane and half god. It meant that Kino would drive his strength against a mountain and plunge his strength against the sea. Juana, in her woman's soul, knew that the mountain would stand while the man broke himself; that the sea would surge while the man drowned in it. And yet it was this thing that made him a man, half insane and half god, and Juana had need of a man; she could not live without a man. Although she might be puzzled by these differences between man and woman, she knew them and accepted them and needed them. Of course she would follow him, there was no question of that. Sometimes the quality of woman, the reason, the caution, the sense of preservation, could cut through Kino's manness and save them all.

when she was suspected to have leaked confidential information from classified Foreign Ministry documents

The Man (2014).
Song lyrics

Quote in an undated letter to Alleta de Jongh, Paris, c. Spring 1912; as cited in Mondrian, - The Art of Destruction, Carel Blotkamp, Reaktion Books LTD. London 2001, p. 243, note 61
1910's

Source: [Freeman calls Black History Month ‘ridiculous’, https://web.archive.org/web/20051217080712/http://www.msnbc.msn.com/id/10482634, Associated Press, New York, December 15, 2005, December 4, 2017]

As quoted in Wisdom for the Soul : Five Millennia of Prescriptions for Spiritual Healing (2006) by Larry Chang, p. 412; this might be a paraphrase, as the earliest occurrence of this phrase thus far located is in the form: "Ronald David Laing has shocked many people when he suggested in 1972 that insanity can be a perfectly rational adjustment to an insane world." in Studii de literatură română și comparată (1984), by The Faculty of Philology-History at Universitatea din Timișoara. A clear citation to Laing's own work has not yet been found.
Disputed

NOW interview (2004)
Context: Maybe there are lots of children or certainly those who are not drawn to my work because they don't want to see those shadows. But, I'm telling what it was like for me. And I know it was not unique for me.
I've known many children, many unhappy and many disturbed children who don't know how to talk about it. And you know, the strangest thing... the fan mail I get from kids are asking me questions which they do not ask their mothers and fathers. Because if they had, why write to me, a perfect stranger?