Burying one s learned borrowings from sources was a craft which one picked up from one s teachers. They did it better and more cunningly than we did, that was the only difference. There is, we would knowingly say, no copyright in ideas. Change the words, but keep the content, and the text is yours. All research finery is borrowed feathers.
Most academics learn to tread the line.
Journalists, in their free and easy profession, have a much more relaxed attitude to intellectual meum and tuum. In conversation, there is no line at all. Students who are still learning where the line is, tend to be the most policed of writers. Universities universally nowadays have public proclamations proscribing plagiarism , outlining, often with great difficulty, what the offence is and the awfulness of committing it. The warnings are apposite.