But let not therefore my good friends be grieved- Among which number, Cassius, be you one- Nor construe any further my neglect Than that poor Brutus with himself at war Forgets the shows of love to other men.
Ben Whishaw's performance of Brutus in this scene shows him being in a trance of contemplation. In his performance as Brutus he only looks away from the book he is reading twice, once when he tells Cassius to not mistake his absent mindedness for neglect. Brutus confirms that he is in conflict by using the metaphor that he is "with himself at war." Brutus looks away from the his book once again as if to share Cassius his conflicted opinions, this can be seen when he slides Cassius a seat and a drink as if to join him.