Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us closer to the secret of the 'Old One.' I, at any rate, am convinced that He is not playing at dice.

Summary

In this quote, the speaker expresses a sentiment of skepticism towards quantum mechanics while indirectly questioning its completeness. They acknowledge the grandeur of the theory but believe that it falls short in uncovering the true nature of the universe, which they refer to as the 'Old One.' They reject the idea that this 'Old One' leaves things purely to chance or plays dice with reality, expressing their conviction that there must be a deeper understanding beyond what quantum mechanics currently provides.