Review: The Variational Principles of Mechanics

> Perhaps the universe is not a computer, perhaps its origin and its conclusion are fixed, and it speeds along a trajectory between the two that, when all possible histories are considered, is the only one it could have...

Perhaps; note that Einstein expended a great deal of effort attempting to patch up this world view in the face of QM, but kept running up against the experimental results that alea iacta est.

(Compare: Aquinas, Leibniz, Spinoza, https://xkcd.com/2904/ )