It was the Usual Suspect, the assumption of an ‘Independent and Separated Observer’, the claim to the Subject-Object Divide.
‘Although the Theory of Relativity makes the greatest demands on the ability of abstract thought, still it permits the traditional requirement of Science, as it permits a division of the world into Subject and Object and hence a clear formulation of the Laws of Causality.
This is the very point at which the difficulties of the Quantum Theory begin’.
Elsewhere, on the method of proper observation, Heisenberg writes:
‘What we observe is not Nature in itself but Nature exposed to our method of questioning’. Hold on to that insight as you read the posts.
The contradictions in Science, always present, came to the fore in the early part of the last century with the arrival of Quantum Physics. [500 years is not out of range historically for old Models to buckle]. Dr. Heisenberg and others were now unabashedly talking about the Observer influencing the Observed.