"We declare war against socialism, not because it is socialism, but because it has opposed nationalism.... We intend to be an active minority, attract the proletariat away from the official Socialist party. But if the middle class thinks that we are going to be their lightning rods, they are mistaken."

"The dangerous persons for the socialist movement are not the intellectuals, but those who are not convinced of socialism. And all those who call themselves socialists without knowing why they are socialists."

"The new society cannot get out of the involucrum of the old society, except by smashing it to pieces; two conceptions, two classes, two worlds will contend for primacy, and only force will compel the weaker to disappear. For this reason, we socialists of the first school, Marxist and catastrophic, if you wish, explain to ourselves the partial violence of to-day and the violence of to-morrow… Do not call us prophets of massacre if we present the possibility that the socialist revolution will have insurrectional episodes. It is puerile to think that such a radical displacement of interests, such a profound transformation of habits can be accomplished without violent conflicts."

"It is blood which moves the wheels of history."

"Do not believe, even for a moment, that by stripping me of my membership card you do the same to my Socialist beliefs, nor that you would restrain me of continuing to work in favor of Socialism and of the Revolution."

"You cannot get rid of me because I am and always will be a socialist. You hate me because you still love me."

"The root of our psychological weakness was this: We socialists have never examined the problems of nations. The International was never concerned with it. The International is dead, paralyzed by events. Ten million proletarians are today on the battlefield."

"What does it matter to the proletarian to understand socialism as one understands a theorem? And is socialism perhaps reducible to a theorem? We want to believe in it; we must believe in it. Humanity needs a credo. It is faith that moves mountains because it gives the illusion that mountains move. Illusion is perhaps the only reality of life."

"The law of socialism is that of the desert: a tooth for a tooth, an eye for an eye. Socialism is a rude and bitter truth, which was born in the conflict of opposing forces and in violence. Socialism is war, and woe to those who are cowardly in war. They will be defeated."

"Socialism has to remain a terrifying and a majestic thing. If we follow this line, we shall be able to face our enemies."

"Socialism is not Arcadian and peaceful. We do not believe in the sacredness of human life."

"The rapacious property-owning American bourgeoisie admits no limits, possesses no scruples and does not share the fears and the cowardice of our bourgeoisie. [They are] violent, absolute criminal. When they feel the need, they simply stain their hands with proletarian blood. They lack any human sense. They are only interested in exploitation."

"For us the national flag is a rag to be planted on a dunghill. There are only two fatherlands in the world: that of the exploited and that of the exploiters."

""Religious man" is an abnormality and "religion" is the certain cause of epidemic diseases of the mind which require the care of alienists."

"The faculty by which man is differentiated from the lower animals is his reasoning power. But the devout believer renounces reason, refuses to explain the things which surround him, the innumerable natural phenomena, because his religious faith is enough for him. The brain loses the habit of thinking; and this religious sottishness hurls mankind back into animalism."

"If today the Middle Ages are retiring into the thick shadows of convents, it is due to triumphant skepticism; and if the epidemic disease of religion no longer appears with the terrible intensity of former times, it is due to the diminution of the political power of the Church."

"The history of many saints, beatified by the church, is repugnant. It shows nothing more than a profound aberration of the human spirit in search of ultra-terrestrial chimeras."

"Religion is a psychic disease of the brain."

"Religious morality shows the original stigmata of authoritarianism precisely because it pretends to be the revelation of divine authority."

"The Bible and morals called Christian are two cadavers."

"How can the idea of a creator be reconciled with the existence of dwarfed and atrophied organs, with anomalies and monstrosities, with the existence of pain, perpetual and universal, with the struggle and the inequalities among human beings?"

"With each new discovery of chemistry, physics, biology, the anthropological sciences, of the practical application of sound principles, dogma collapses. It is a part of that old edifice of religion which crumbles and falls in ruins."

"When we claim that "God does not exist," we mean to deny by this declaration the personal God of theology, the God worshiped in various ways and divers modes by believers the world over, that God who from nothing created the universe, from chaos matter, that God of absurd attributes who is an affront to human reason."

"The struggle against the religious absurdity is more than ever a necessity today."

"Militarism! Here is the monstrous leech that is incessantly sucking the blood of the people and its best energy! Here is the target for our attacks! We must put an end to barbarism, proclaim that the army is now a highly organized school of crime and that it exists solely to protect bourgeois capital and profits. We must not be deterred from proclaiming ourselves international socialists. We recognize no borders and no flags, we hate all steel, every institution that exist to kill men, waste energy, strangle the advance of the workers."

"Marx was the greatest of all theorists of socialism."

"Science is now in the process of destroying religious dogma. The dogma of the divine creation is recognized as absurd."