I want to know the answer to the following question:
What well known socialist adopted the usage of this term in Germany?
All the background I'm provided with is that "At about the same time, the word "humanism" as a philosophy centred on humankind (as opposed to institutionalised religion) was also being used in Germany by the so-called Left Hegelians, Arnold Ruge, and Karl Marx, who were critical of the close involvement of the church in the repressive German government.". Is that enough to answer the question?
Answer: yes