Ideas improve. The meaning of words participates in the improvement. Plagiarism is necessary. Progress implies it. It embraces an author's phrase, makes use of his expressions, erases a false idea, and replaces it with the right idea.
“To become a popular religion, it is only necessary for a superstition to enslave a philosophy.”
“It is by universal misunderstanding that all agree. For if, by ill luck, people understood each other, they would never agree.”