The deep irony here is that eventually, Einstein reneged on this very belief of his, refusing to accept Quantum Mechanics, and searching for a Unified Field Theory, despite QM being highly successful with predictions, as well as informative about nature, and despite there being little success with developing a UFT: there were facts of experience set forth by external conditions of the field of science and the associated knowledge that he couldn't incorporate into his conceptual world, and thus likely missed out on potentially many more opportunities to put his mark on science via taking great strides forward, where the pathways were clearer, and less obstructed.