If i said that the following is my own idea and thoughts, then this is called plagiarism "an act or instance of using or closely imitating the language and thoughts of another author without authorization and the representation of that author's work as one's own, as by not crediting the original author:
It is said that he plagiarized Thoreau's plagiarism of a line written by Montaigne.
Synonyms: appropriation, infringement, piracy, counterfeiting; theft, borrowing, cribbing, passing off." (http://www.dictionary.com/browse/plagiarism, 2017). in other words it is the process of stealing or raping the words or thoughts of other people.
This happens very often in universities because some students buy and copy and steal articles and scientific ideas in order to complete their university assignments.
finally there is a tolerance of plagiarism which is accepted as it could be considered as telepathic of thoughts and it happen a lot. However the accepted limits of plagiarism variate from university to another.