This is from physicist Sean Carroll :

"The status of the Born Rule depends greatly on one’s preferred formulation of quantum mechanics. When we teach quantum mechanics to undergraduate physics majors, we generally give them a list of postulates that goes something like this:

1. Quantum states are represented by wave functions, which are vectors in a mathematical space called Hilbert space.
2. Wave functions evolve in time according to the Schrödinger equation.
3. The act of measuring a quantum system returns a number, known as the eigenvalue of the quantity being measured.
4.The probability of getting any particular eigenvalue is equal to the square of the amplitude for that eigenvalue.
5. After the measurement is performed, the wave function “collapses” to a new state in which the wave function is localized precisely on the observed eigenvalue (as opposed to being in a superposition of many different possibilities)."

@PGJ : Notice that Carroll is referring to our ability to measure quantum states accurately. Not to the existence of quantum states. You are trying (in your posts here and on other forums) to apply the above rule to human logic, morals, beliefs, etc. That alone is fallacious. To use this law to say that we can not determine reality is silly. Our measurements are subject to doubt but real is real. The universe will continue to be real long after the measurers become extinct.