A Chinese gift of a statue of Karl Marx is dividing Germans, as his home town of Trier prepares to unveil it 200 years after his birth.
Marx co-wrote the Communist Manifesto, which said that all human history had been based on class struggle.
His work remains controversial in Europe but is presented by China as central to its way of governing.
Local officials have appealed for calm as rival groups prepare for rallies in Trier on Saturday.
They include anti-communist and anti-capitalist demonstrations as well as a vigil in solidarity with China's banned Falun Gong movement, DPA news agency reports.
"If you want to criticise Marx, you are welcome to do so, but not with violence or destructive rage," Trier spokesman Michael Schmitz told DPA.
Why is Marx controversial?
His theories were used by his followers to form the basis of communism, a system under which everything was to be owned communally and social classes would disappear.
However communist-run regions and states such as the Soviet Union and China became notorious for repression and human rights abuses.
Germany's eastern half was ruled under the Soviet Union from 1949 until reunification in 1990, by which time it was much poorer than its western counterpart.
Malu Dreyer, leader of Germany's Rhineland-Palatinate state, has said the commemorations of Marx's birth are an opportunity to discuss the man and his work, not to "celebrate" him.
But speaking in Trier on Friday, European Commission President Jean-Claude Juncker said Marx today "stands for things which he is not responsible for and which he didn't cause because many of the things he wrote down were redrafted into the opposite".
There has been a revival of interest in Marxist theory in the wake of the 2008 global financial crash.
What's the problem with the statue?
Trier officials said disputes about taking the 4.5m (15ft) statue had dragged on for two years because some argued that accepting it was not compatible with criticising alleged human rights abuses in China.
On Friday the German branch of the writers organisation Pen said the statue should not be unveiled until Liu Xia, the widow of China's Nobel Peace Prize winner Liu Xiaobo, was released from house arrest.
Ms Liu has been confined to her home since 2010. She has never been charged with any crime.
"We have accepted it as a gesture of friendship and this statue should encourage people to deal with Karl Marx," Trier Mayor Wolfram Leibe said, adding: "Maybe some judgements and prejudices will be revised."
There are other monuments to Marx in Germany, including the house of his birth and a statue in a park in the capital Berlin. About 4.5m tourists including 50,000 from China visit Trier, Mr Leibe said.
What does China think of Marx?
President Xi Jinping on Friday gave a high-profile speech praising Marx as the greatest thinker of modern times.
He urged China's ruling Communist Party to go back to the roots of Marxism and said the Chinese communist party would forever remain its "guardians and practitioners".
Students and most civil servants in China have to complete mandatory courses in Marxist theory.
Despite this, China's capitalist system is home to hundreds of billionaires and a widening gap between rich and poor.
Who was Karl Marx?
The son of a Jewish lawyer in Germany, Marx became a revolutionary communist in Paris and met his lifelong collaborator Friedrich Engels there
They co-wrote the Communist Manifesto, which asserted that all human history had been based on class struggle and the workers of the world would ultimately seize power from the ruling elites
Marx then moved to London and wrote Das Kapital, arguing that an economic system based on private profit was inherently unstable. Workers were exploited by factory owners and did not own the products of their labour, he said, making them little better than machines
In the UK, Labour Party leader Jeremy Corbyn has described Marx as a "fascinating figure", saying he had "observed a great deal" and a "great deal" could be learnt from him
Marx died in 1883 and was buried at London's Highgate Cemetery