“Swearing's my release, and the one weapon I have to defend myself against destiny when it elects to strike without pity.”

The Tragic Sense of Life (1913), VI : In the Depths of the Abyss
Context: I will not say that the more or less poetical and unphilosophical doctrines that I am about to set forth are those which make me live; but I will venture to say that it is my longing to live and to live for ever that inspires these doctrines within me. And if by means of them I succeed in strengthening and sustaining this same longing in another, perhaps when it is all but dead, then I shall have performed a man's work, and above all, I shall have lived. In a word, be it with reason or without reason or against reason, I am resolved not to die. And if, when at last I die out, I die altogether, then I shall not have died out of myself — that is, I shall not have yielded myself to death, but my human destiny shall have killed me. Unless I come to lose my head, or rather my heart, I will not abdicate from life — life will be wrested from me.

PV, p. 73; SV1, XIII, p. 559; Jon Bartley Stewart. 2008. Johan Ludvig Heiberg: Philosopher, Littérateur, Dramaturge, and Political Thinker. Museum Tusculanum Press.
Disputed

As quoted in The Day After Trinity: J. Robert Oppenheimer and the Atomic Bomb (1981), a documentary film directed by Jon Else, written by David Peoples, Janet Peoples, and Jon Else.
Context: I have felt it myself. The glitter of nuclear weapons. It is irresistible if you come to them as a scientist. To feel it's there in your hands, to release this energy that fuels the stars, to let it do your bidding. To perform these miracles, to lift a million tons of rock into the sky. It is something that gives people an illusion of illimitable power, and it is, in some ways, responsible for all our troubles — this, what you might call technical arrogance, that overcomes people when they see what they can do with their minds.

Last Speech to the National Convention (26 July 1794)

General election address (January 1974).
Tebbit, p. 168.

Garantissez-moi de mes amis, écrivait Gourville proscrit et fugitif, je saurai me défendre de mes ennemis. ("Defend me from my friends," wrote Gourville, exile and fugitive, "I can defend myself from my enemies.") — Gabriel Sénac de Meilhan, Considérations sur l'esprit et les moeurs (1788): "De L'Amitié." Sénac de Meilhan was quoting Jean Hérault, sieur de Gourville (1625 - 1703).
The remark has often been attributed to Voltaire and to Claude-Louis-Hector de Villars.
Misattributed

Katniss, p. 189
Source: The Hunger Games trilogy, Catching Fire (2009)

The Trouble With Being Born (1973)

As quoted in Sophia, Living and Loving: Her Own Story (1979) by A. E. Hotchner, p. 76.
Context: I was blessed with a sense of my own destiny. I have never sold myself short. I have never judged myself by other people’s standards. I have always expected a great deal of myself, and if I fail, I fail myself. So failure or reversal does not bring out resentment in me because I cannot blame others for any misfortune that befalls me.