In the movie Arrival a linguist learning an alien language gains access to a consciousness that knows the future. Unlike our consciousness, which runs from cause to effect and is sequential, theirs can see the whole arc of time simultaneously.Their life is about discerning purpose and enacting events, while ours is about discerning good outcomes and deploying our free will and volition to those ends.
In Ted Chiang’s Story of Your Life, on which the screenplay is based, this is explained theoretically with reference to Fermat’s principle of least time. This states that the path taken by a ray between two given points is the path that can be traversed in the least time. Lurking behind this idea is the realisation that nature has an ability to test alternative paths: a ray of sunlight must know its destination in order to choose the optimal route. Chiang has his protagonist muse about the nature of free will in such a scheme: the virtue would not be in selecting the right actions, but in duly performing already known actions, in order that the future occurs as it should. It’s a bit like an actor respecting Shakespeare enough not to improvise one of his soliloquies. Read More