John Archibald Wheeler Quote
Nature at the quantum level is not a machine that goes its inexorable way. Instead what answer we get depends on the question we put, the experiment we arrange, the registering device we choose. We are inescapably involved in bringing about that which appears to be happening.
In: John Archibald Wheeler and Wojciech Hubert Zurek (eds.), Quantum Theory and Measurement (p. 185)