Complex sentence: While Winston eventually learns that The Book is the product of an Inner Party committee that includes O'Brien, whether Goldstein or his Brotherhood are real or fabrications of Party propaganda is something that neither Winston nor the reader is permitted to know.
Split into simpler sentences: While Winston eventually learns that The Book is the product of an Inner Party committee that includes O'Brien. Whether Goldstein or his Brotherhood are real or fabrications of Party propaganda is something that neither Winston nor the reader is permitted to know.