“There are no whole truths; all truths are half-truths. It is trying to treat them as whole truths that plays the devil.”

23 October 1929, From a letter to a Muslim disciple
India's Rebirth
Context: You say that you ask only for the Truth and yet you speak like a narrow and ignorant fanatic who refuses to believe in anything but the religion in which he was born. All fanaticism is false, because it is a contradiction of the very nature of God and of Truth. Truth cannot be shut up in a single book, Bible or Veda or Koran, or in a single religion. The Divine Being is eternal and universal and infinite and cannot be the sole property of the Mussulmans or of the Semitic religions only, — those that happened to be in a line from the Bible and to have Jewish or Arabian prophets for their founders. Hindus and Confucians and Taoists and all others have as much right to enter into relation with God and find the Truth in their own way. All religions have some truth in them, but none has the whole truth; all are created in time and finally decline and perish. Mahomed himself never pretended that the Koran was the last message of God and there would be no other. God and Truth outlast these religions and manifest themselves anew in whatever way or form the Divine Wisdom chooses. You cannot shut up God in the limitations of your own narrow brain or dictate to the Divine Power and Consciousness how or where or through whom it shall manifest; you cannot put up your puny barriers against the divine Omnipotence. These again are simple truths which are now being recognised all over the world; only the childish in mind or those who vegetate in some formula of the past deny them. You have insisted on my writing and asked for the Truth and I have answered. But if you want to be a Mussulman, no one prevents you. If the Truth I bring is too great for you to understand or to bear, you are free to go and live in a half-truth or in your own ignorance. I am not here to convert anyone; I do not preach to the world to come to me and I call no one. I am here to establish the divine life and the divine consciousness in those who of themselves feel the call to come to me and cleave to it and in no others.

Sermon (1899)

Alan Dershowitz, The Best Defense (New York: Vintage), 1983-5-12, p. xiv.

"A Man of the People", p. 140
Four Ways to Forgiveness (1995)
Context: “Lines and colors made with earth on earth may hold knowledge in them. All knowledge is local, all truth is partial,” Havzhiva said with an easy, colloquial dignity that he knew was an imitation of his mother, the Heir of the Sun, talking to foreign merchants. “No truth can make another truth untrue. All knowledge is a part of the whole knowledge. A true line, a true color. Once you have seen the larger patttern, you cannot go back to seeing the part as the whole."

The Kasîdah of Hâjî Abdû El-Yezdî (1870)

Encyclical Fides et Ratio, 14 September 1998

Source: www.vatican.va http://www.vatican.va/holy_father/john_paul_ii/encyclicals/documents/hf_jp-ii_enc_14091998_fides-et-ratio_en.html

Part of this is often misquoted as "We have nothing to fear but fear itself," most notably by Martin Luther King, Jr. in his I've Been To The Mountaintop http://www.americanrhetoric.com/speeches/mlkivebeentothemountaintop.htm speech. Similar expressions were used in ancient times, for example by Seneca the Younger (Ep. Mor. 3.24.12 http://www.thelatinlibrary.com/sen/seneca.ep3.shtml): scies nihil esse in istis terribile nisi ipsum timorem ("You will understand that there is nothing dreadful in this except fear itself"), and by Michel de Montaigne: "The thing I fear most is fear", in Essays (1580), Book I, Ch. 17.
1930s, First Inaugural Address (1933)
Context: This is preeminently the time to speak the truth, the whole truth, frankly and boldly. Nor need we shrink from honestly facing conditions in our country today. This great Nation will endure as it has endured, will revive and will prosper. So, first of all, let me assert my firm belief that the only thing we have to fear is fear itself — nameless, unreasoning, unjustified terror which paralyzes needed efforts to convert retreat into advance. In every dark hour of our national life a leadership of frankness and vigor has met with that understanding and support of the people themselves which is essential to victory.

91
95 poems (1958)

To his brother Louis, commenting on The Count of Egmont's visit to Philip II about the problems in the Netherlands (1565), as quoted in William the Silent (1897) by Frederic Harrison, p. 22