Who said or wrote: "If I have seen further it is by standing on the shoulders of giants"?
It was written—or at least quoted—by a man often considered the greatest scientist ever, Sir Isaac Newton.
Newton's views on optics were met by a lot of criticism when they were first presented in the late 1600s. His discovery that white light was made up of small particles of differing sizes that could be split into colors of the rainbow by a prism was quite unique and his views were in direct conflict with many scientists of the day.
He modestly attributed his discoveries to the work done by his predecessors. Newton explained in a letter that, if he had seen further than other men, "it is by standing on the shoulders of giants."
British scholars, however, have traced the phrase "standing on the shoulders of giants" back to the 12th century and philosopher Bernard of Chartres.