Plagiarism, by the English oxford dictionary, edition 6, was defined as the act plagiarizing, that is copying another persons ideas, words or works and pretend that they are your own
So for me, from this explanation, you can only pretend that they are your own only if you are fully aware that they are not yours. So sometimes, you might just use someone's work maybe coincidentally, but it should not be accounted for as plagiarism. Let me sight some examples
- During the last year campaign for the USA presidential election, Melania trump gave a speech in the 2016 Republican National Convention, it appeared to have plagiarised the then first lady Mitchell Obama's speech to the Democratic National Convention in 2008. In her speech, she said that from a young age, her parents impressed on her the values of working hard to get what you want, and that your word is your bond, to do what you say and keep your promises, and to treat people with respect. Coincidentally, Mitchelle Obama speech had contained very similar if not the same content too, but can you say Trump plagiarised? No, even as children, our parents taught all of us to grow with good values, so its not much of a coincidence that they both grew with the same values impressed on them.
- Now in 1958, Chinue Achebe, Nigeria's most famous novelist and also one of Africa's most renowned, published a novel titled 'Things Fall Apart' . it had sold more than 8 million copies worldwide. Then came 2010, popular American artiste, 50 cent, was about releasing a film with the same title. He claimed to have never heard of the novel, that he had spent the year writing the film,. He even offered to pay $1 million, for the name to remain unchanged, but Chinue Achebe refused,. He ended up changing it to 'How Things Fall Apart'.
But then a times plagiarism comes in handful, like in the case of Martin Luther King, as you stated above, even after his work was proved to contain some content of plagiarism, the school refused to revoke his degree, saying that his dissertation, despite its short coming, had contributed a lot to the field..