What makes a PhD researcher?

One friend who does his PhD in an interdisciplinary field of natural sciences at Cambridge quotes from his professor, 'A scholar reads and a researcher does (experiments)'. I find it also true in the case of humanities as 'a scholar reads and a researcher writes'.However, doing researches is by nature a paradoxical process between reading and writing.

The PhD studies seem to be the circle of knowledge that Socrates drew. "The more you know, the more you realise that you know nothing".One starts with great curiosity into a specific QUESTION yet only to end up with a PROBLEM. He might be delighted to find one answer to the initial question but be dazzled by all the controdictory answers as he reads on and on. The worse situation is that all those sparkling ideas of novelty that inspired one's studies prove to be banal when he reads the works of several decades' old. Then comes the problem of sorting out the answers and finding one's own POSITION to see the initial question since 'theory' etymologically means the way to SEE things. The problem for a PhD candidate is not longer answering a simple question be to find solutions to frame the object of study and present the whole picture in his own way, where the 'originality' of his work stands.