as a screenwriter, he is notable for his collaborations with director martin scorsese, particularly "the age of innocence" and "gangs of new york" — a screenplay he started working on in 1976 — as well as kathryn bigelow's "strange days". he did an uncredited rewrite of james cameron's screenplay for "titanic" and was, with scorsese, the co-screenwriter of "silence". cocks and scorsese approached author philip k. dick in 1969 for an adaptation of his 1968 novel "do androids dream of electric sheep?" though the duo never optioned the book, it was later developed into the movie "blade runner" by screenwriter hampton fancher and director ridley scott.