“The various positivities produced ... by the logic of political hope depend on the mathematical illusion that negated negations might somehow escape, and not redouble, such negativity.”

Anarchist Manifesto (1850)
Context: Indeed:
Who says anarchy, says negation of government;
Who says negation of government, says affirmation of the people;
Who says affirmation of the people, says individual liberty;
Who says individual liberty, says sovereignty of each;
Who says sovereignty of each, says equality;
Who says equality, says solidarity or fraternity;
Who says fraternity, says social order;
By contrast:
Who says government, says negation of the people;
Who says negation of the people, says affirmation of political authority;
Who says affirmation of political authority, says individual dependency;
Who says individual dependency, says class supremacy;
Who says class supremacy, says inequality;
Who says inequality, says antagonism;
Who says antagonism, says civil war;
From which it follows that who says government, says civil war.

Source: Das Ressentiment im Aufbau der Moralen (1912), L. Coser, trans. (1973), p. 67

This proposition is infinitely important; only, negation as such is formless abstraction. However, speculative philosophy must not be charged with making negation or nothing an ultimate: negation is as little an ultimate for philosophy as reality is for it truth. Of this proposition that determinateness is negation, the unity of Spinoza's substance — or that there is only one substance — is the necessary consequence. Thought and being or extension, the two attributes, namely, which Spinoza had before him, he had of necessity to posit as one in this unity; for as determinate realities they are negations whose infinity is their unity. According to Spinoza's definition, of which more subsequently, the infinity of anything is its affirmation. He grasped them therefore as attributes, that is, as not having a separate existence, a self-subsistent being of their own, but only as sublated, as moments; or rather, since substance in its own self lacks any determination whatever, they are for him not even moments, and the attributes like the modes are distinctions made by an external intellect.
Georg Wilhelm Friedrich Hegel, The Science of Logic, 1812
G - L, Georg Wilhelm Friedrich Hegel

Part I, Section 14
Principles of Philosophy of the Future http://www.marxists.org/reference/archive/feuerbach/works/future/index.htm (1843)

Variant: The human mind has a primitive ego defense mechanism that negates all realities that produce too much stress for the brain to handle. It’s called Denial.
Source: Inferno

"No Self Surrender"
What Buddhists Believe (1993)

Source: Story: Substance, Structure, Style, and the Principles of Screenwriting

in [Quantum Optics for Engineers, CRC, New York, 2013, 978-1439888537, F. J. Duarte]