Arcadia takes on the age-old fate vs. free will argument from a scientific standpoint: if we can take a system and use the laws of physics to predict exactly what will happen in that system, why can't we do the same for our brains? And if the atoms in our brains are mindlessly knocking against each other like a bunch of Newtonian billiard balls, then where do we get off thinking we have free will? Of course, things get very complicated very quickly when the human brain is involved – but Arcadia is not a play to shy away from complication.
Arcadia portrays science as an attempt to figure out fate, while literature rebels against the idea of predetermination.
Arcadiarepresents "will" that is not "free": the characters' choices are always determined by their personalities and their historical situations.