“Partly through learning about physics theories like Fermat’s Principle of Least Time, Banks deduces that the heptapods cannot begin communicating, or acting, until they first know how that communication or action will ultimately end. In short: they experience time not sequentially, but all at once:
“…by viewing events over a period of time, one recognized that there was a requirement that had to be satisfied, a goal of minimizing or maximizing. And one had to know the initial and final states to meet that goal; one needed knowledge of the effects before the causes could be initiated…
“We experienced events in an order, and perceived their relationship as cause and effect. They experienced all events at once, and perceived a purpose underlying them all. A minimizing, maximizing purpose.”