verb tense in sentence structure

Roe's argument is "trapped" in time, just as are works of fiction, movies, etc. The present tense is used in such cases. Similary, a redefinition, once captured in writing, remains in the present.

Actually, the proper use of tense in the sample sentence lies between the explanations provided by Lewis and Mallory. Mallory correctly describes the use of the "literary present tense" where works of fiction (etc.) are "trapped" in an eternal present. The academic standard for use of tense is slightly different when writing concerning history. There, you must answer several questions in order to determine the proper tense.

Are you writing about Roe's argument as an event in history? If yes, then the sentence might be: "In 1964, Roe first argued that ..." You use the past tense, because you are speaking of Roe's act of writing (or arguing), and that event occurred in the past. Additionally, Lewis's point then comes into play. Is a redefinition still required, or has it been accomplished? If it has not, then Roe's argument remains valid, and the proper tense is "redefinition is needed." If the redefinition has occurred, the sentence becomes "redefinition was needed."

A different calculation takes place if Roe is not an actor in your historical text, but instead Roe is another observer of your historical topic. In this case, your next question becomes -- is Roe's observation still valid. If yes, you treat Roe's commentary as existing in the eternal present: "Roe argues that ... redefinition is required." This is true even if Roe is long dead. However, if Roe's observations have been discredited, then you are actually writing about Roe as an event in the past and not as a timeless observer. In this case, the past tense should be used as described in the previous paragraph.

Unfortunately, we do not know enough about the context of the sample sentence to suggest which is the right tense for the context.