The Paradox of Backward Causation in Quantum Mechanics

Backward causation generates all kinds of paradoxes, doesn't it? One person who thought about those kinds of puzzles 50 or 60 years ago was the Oxford philosopher Michael Dummett. What Dummett noticed was that as long as I can't find out about whether the thing I think I can affect in the past actually happened or not before I decide whether to try to bring it about then you can't get those kinds of paradoxical loops going. And I think it's that loophole that quantum mechanics exploits.