Sentence:  He and also Mr. Cowley and Mr. Warren have fallen to the temptation which besets many of us to read into our authors - Nathaniel Hawthorne , for example , and Herman Melville - protests against modernism , material progress , and science which are genuine protests of our own but may <WSD>not</WSD> have been theirs . 
Meaning of the word marked with <WSD> tags:  negation of a word or group of words