

"Thieves." "Parasites." "Exploiters." The over two dozen socialist thinkers quoted below use these and other terms of derision when describing slackers and slacking.
These celebrated socialists not only say slackers should be considered thieves but also that slackers should be "dealt with as such." They say the lazy should be "put under surveillance" and "compelled to work" and that those who do not work "shall not eat."
(The sources for the quotes below are found in our paper, "Why Socialism Says Slacking Is Theft.")
Some acts were not crimes under capitalism, for example, laziness…. However, in our society, it is an antisocial and criminal condition which goes against the interests of the masses. These are new types of crimes.
— Fidel Castro
As typical of numerous socialists, Castro attacks slackers and slacking time and again. "Learning From Fidel" provides over thirty examples of this celebrated socialist excoriating "slackers," "loafers," and "the lazy."
They are slackers, that is to say thieves.
— Henri de Saint-Simon
The slacker, the idler, who, without performing any social task, enjoys like others—and often more than others—the products of society, must be pursued as a thief and parasite. We owe it to ourselves to give him nothing; but since he must nevertheless live, to put him under surveillance, and compel him to work.
— Pierre-Joseph Proudhon
[Socialism must take] drastic measures to eliminate the parasites, be they ones who hide in their attitude a deep hostility towards socialist society or ones who are irredeemably against work.
— Che Guevara
Idleness will be suppressed.
—Charles Peguy
Idlers must vanish; only useful social workers will remain…. Slovenliness and cheating at work at present is a crime against the working class. Compulsory labor service is indispensable.
—Nikolai Bukharin
No one can, without committing a crime, shirk labor.
— Grachhus Babeuf
Idleness and laziness are as vile to us as theft.
— Étienne Cabet
Any person who neglects or refuses to pay this debt [to society] by contributing to his ability to satisfying the needs of the present or future generations is held to be a thief, and will be dealt with as such.
— Beatrice Webb
Not one serious Socialist will begin to deny to the Labor State the right to lay its hand upon the worker who refuses to execute his labor duty.
— Leon Trotsky
In one place … half a dozen workers who shirk their work … will be put in prison. In another place they will be put to cleaning latrines. In a third place they will be provided with "yellow tickets" after they have served their time, so that everyone shall keep an eye on them, as harmful persons, until they reform. In a fourth place, one out of every ten idlers will be shot on the spot.
— Vladimir Lenin
HOW TO MOBILIZE SLACKERS TO TAKE PART IN PRODUCTION … Our method of mobilization re: … The government gives them definite production tasks … They are inspected at regular intervals. … Urging the masses to struggle against them, and to force them to join production. … Organizing loafers into collective production … The masses were very pleased that the government made the slackers take part in production.
— Mao Zedong
'He who does not work shall not eat.' On this all Socialists are agreed. … But if work is a necessity, no one shall be exempt from it. For if there are exceptions, it would mean that those who do work will have to contribute more than their share to the common stock. Besides, on what principle are the exceptions to be justified?
— Werner Sombart
[one must] work in order to be able to eat.
— Karl Marx

Our paper "Karl Marx's 'Education of the Future'" reviews Marx's repeated calls for child labor as "education," one of the benefits Marx listed being that it would teach all that one must "work in order to be able to eat." It also studies how today's socialists have disappeared Marx's demands for child labor as they attempt to portray him as a "democratic socialist."
Idlers, shirkers of work, exist in bourgeois [capitalist] society only.
— August Bebel
The idler will be treated not only as a rogue and a vagabond, but as an embezzler of national funds, the meanest sort of thief.
— Bernard Shaw
As long as there is an idler vegetating in this world, society will be in peril.
— Richard Lahautière
How many slackers are there who try to disguise their parasitism, by taking the look of the intellectual laborer!
—Emile Vandervelde
There will be no idlers, all will produce more than they consume.
— Charles Fourier
In cooperation for life, the slacker becomes synonymous with the thief.
— Georges Renard
[Under socialism] … the disgrace with which public opinion would brand the lazy man, and the severity of the law, … would punish voluntary idleness with such pains as are now inflicted on thieves.
— Philip Buonarotti
When I say that in traditional African society everybody was a worker, I do not use the word 'worker' simply as opposed to 'employer' but also as opposed to 'loiterer' or 'idler' …. Not only was the capitalist, or the landed exploiter, unknown to traditional African society, but we did not have that other form of modern parasite – the loiterer, or idler, who accepts the hospitality of society as his 'right' but gives nothing in return! … There is no such thing as socialism without work.
—Julius Nyerere
The one who evades or scamps his work robs every one of his fellows.
— Edward Bellamy
The first step to be taken then is to abolish a class of men privileged to shirk their duties as men, thus forcing others to do the work which they refuse to do. All must work according to their ability, and so produce what they consume. [Morris's friend and fellow socialist Bernard Shaw writes of Morris: "he held that people who do not do their fair share of social work are 'damned thieves.']
— William Morris
One of the reasons for a worker's state is to sternly enforce the principle, 'He who does not work shall not eat.'
— Max Shachtman
From idleness to laziness and from one to the other to all vices and all disorders, there is only one step. A man who does not give his production to the association is more than useless, he harms.
— Constantin Pecqueur
In the Millennium state [that is, socialist society], Idleness and Uselessness will be unknown in the conduct of a single individual.
— Robert Owen
All loafers must be reformed into good citizens through participation in production.
— Mao Zedong
The socialist principle: "He who does not work, neither shall he eat."
—Vladimir Lenin
Socialist thinkers who call slackers "thieves" and "parasites" aren't expressing a personal opinion. They're stating a given outcome of socialist philosophy—an automatic byproduct of socialism's foundation on the anti-liberal duty of "from each according to their ability."