Friedrich Engels was a 19th-century German political philosopher who developed communist theory alongside his better-known collaborator, Karl Marx, co-authoring The Communist Manifesto (1848).

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• Political economy came into being as a natural result of the expansion of trade, and with its appearance elementary, unscientific huckstering was replaced by a developed system of licensed fraud, an entire science of enrichment.
  • Outlines of a Critique of Political Economy (1843)

• The slave frees himself when, of all the relations of private property, he abolishes only the relation of slavery and thereby becomes a proletarian; the proletarian can free himself only by abolishing private property in general.
  • Principles of Communism (1847)

• What is Communism? Communism is the doctrine of the conditions of the liberation of the proletariat. What is the proletariat? The proletariat is that class in society which lives entirely from the sale of its labor and does not draw profit from any kind of capital; whose weal and woe, whose life and death, whose sole existence depends on the demand for labor....
  • Principles of Communism (1847)

• How do you think the transition from the present situation to community of Property is to be effected?

The first, fundamental condition for the introduction of community of property is the political liberation of the proletariat through a democratic constitution.

• • Draft of a Communist Confession of Faith (1847)

• There is no country in Europe which does not have in some corner or other one or several ruined fragments of peoples, the remnant of a former population that was suppressed and held in bondage by the nation which later became the main vehicle of historical development. These relics of a nation mercilessly trampled under foot in the course of history, as Hegel says, these residual fragments of peoples always become fanatical standard-bearers of counter-revolution and remain so until their complete extirpation or loss of their national character, just as their whole existence in general is itself a protest against a great historical revolution.
  • Engels in Neue Rheinische Zeitung, No. 194 (January 13, 1849)

• Ireland still remains the Holy Isle whose aspirations must on no account be mixed with the profane class-struggles of the rest of the sinful world ... the Irish peasant must not on any account know that the Socialist workers are his sole allies in Europe.
  • Letter to Karl Marx http://www.marxists.org/archive/marx/works/1869/letters/69_12_09.htm (December 9, 1869)

• Labour is the source of all wealth, the political economists assert. And it really is the source -- next to nature, which supplies it with the material that it converts into wealth. But it is even infinitely more than this. It is the prime basic condition for all human existence, and this to such an extent that, in a sense, we have to say that labour created man himself.
  • The Part Played by Labour in the Transition from Ape to Man (1876)

• Only sound common sense, respectable fellow that he is, in the homely realm of his own four walls, has very wonderful adventures directly he ventures out into the wide world of research.
  • Anti-Dühring (1878)

• Freedom does not consist in any dreamt-of independence from natural laws, but in the knowledge of these laws, and in the possibility this gives of systematically making them work towards definite ends.
  • Anti-Dühring (1878)

• Hegel was the first to state correctly the relation between freedom and necessity. To him, freedom is the insight into necessity.
  • Anti-Dühring, pt. 1, ch. 11 (1878)

• The state is not “abolished,” it withers away.
  • Anti-Dühring, pt. 3, ch. 2 (1878)

• By bourgeoisie is meant the class of modern capitalists, owners of the means of social production and employers of wage labor. By proletariat, the class of modern wage laborers who, having no means of production of their own, are reduced to selling their labor power in order to live.
  • The Communist Manifesto, footnote (1888 edition)

• Just as Marx used to say about the French Marxists of the late ’seventies: All I know is that I am not a Marxist.
  • Letter to Conrad Schmidt http://www.marxists.org/archive/marx/works/1890/letters/90_08_05.htm (August 5, 1890)

• What each individual wills is obstructed by everyone else, and what emerges is something that no one willed.
  • Letter to Jean-Richard Bloch http://www.marxists.org/archive/marx/works/1890/letters/90_09_21.htm (September 21, 1890)

• People think they have taken quite an extraordinarily bold step forward when they have rid themselves of belief in hereditary monarchy and swear by the democratic republic. In reality, however, the state is nothing but a machine for the oppression of one class by another, and indeed in the democratic republic no less than in the monarchy.
  • Introduction to 1891 edition of Karl Marx's, The Civil War in France

• The first act by virtue of which the State really constitutes itself the representative of the whole of society—the taking possession of the means of production in the name of society—this is, at the same time, its last independent act as a State. State interference in social relations becomes, in one domain after another, superfluous, and then dies out of itself; the government of persons is replaced by the administration of things, and by the conduct of processes of production. The State is not “abolished.” It dies out.
  • Socialism, Utopian and Scientific (1901)

The Condition of the Working Class in England in 1844 (1845)

• The way in which the vast mass of the poor are treated by modern society is truly scandalous. They are herded into great cities where they breathe a fouler air than in the countryside which they have left.

• How is it possible that the poorer classes can remain healthy and have a reasonable expectation of life under such conditions? What can one expect but that they should suffer from continual outbreaks of epidemics and an excessively low expectation of life? The physical condition of the workers shows a progressive deterioration.