  To refute the primacy of essence over existence, Khayyam offers an argument based on the relationship between subject and predicate. He argues that “Existence exists and does not need another existence;” (Risālah fi'l-wujūd) but, cognizant of the counterargument, he also states that one may object by saying that the same argument holds true with regard to essence. So one can say, “A man is a man through man-ness and man-ness does not need another man-ness to be man-ness” (Risālah fi'l-wujūd).