Why did Albert Einstein object to the probabilistic interpretation of quantum mechanics?

Albert Einstein’s objection to the probabilistic interpretation of quantum mechanics was rooted in his commitment to deterministic causality. He famously argued that "God does not play dice with the universe," expressing his belief that the physical world should be governed by predictable, objective laws rather than inherent randomness.123

Einstein viewed the Copenhagen interpretation—which posits that probabilistic outcomes are fundamental to nature—as physically incomplete. He believed that if a theory could not provide a precise, deterministic description of physical reality, it must be missing underlying "elements of reality".54

Throughout his life, Einstein engaged in rigorous debates with Niels Bohr and other physicists, utilizing thought experiments like the EPR paradox to challenge the theory's consistency. While he eventually sought to incorporate quantum phenomena into a unified field theory, he remained steadfast in his conviction that the renunciation of deterministic causality was a fundamental flaw in the standard understanding of the atomic world.35