Laplace had said that from a complete and detailed knowledge of the universe the future could be predicted, but [Heisenberg's] uncertainty principle shows that it is impossible to have such a detailed knowledge. The whole deterministic hypothesis therefore collapses; human free will can no longer be denied.
~Keith J. Laidler The World of Physical Chemistry Oxford University Press: 1981
I believe that I knew each "piece" of that reasoning separately but never came to that simple conclusion. How could I have missed something that obvious? Or have I just forgotten it?