Utterances of this kind would naturally in many minds evoke the impression of an underlying mysticism foreign to the spirit of science; at the [Copenhagen Congress for the Unity of Science] in 1936 I therefore tried to clear up such misunderstandings. ... Yet, I am afraid that I had in this respect little success in convincing my listeners, for whom the dissent among the physicists themselves was naturally a cause of skepticism.

Bohr takes it back: After the famous 1927 Solvay Congress, Einstein accused Bohr of tainting quantum physics with subjectivity and mysticism, both of which are incompatible with science. Bohr spent most of the rest of his life denying this charge and blaming it on misunderstandings. About his mystical statements, he says

The groundless character of mystical beliefs of some great physicists shows up in the contradictory and indecisive statements they make regarding those beliefs. While they don't even have to defend their science because of its firm foundation in facts and verifiable observation, they waver when pressed on their mysticism to the point that they sometimes take back their beliefs.

Schrödinger's disclaimer: In the preface of his collection of essays on life, mind, and matter, Schrödinger laments the specialization forced on science by the enormity of knowledge and yearns the days -- perhaps in pre-Renaissance Europe -- when the institutions of higher learning (universities) were named after the all-embracing (universal) knowledge. He points to the spread of multifarious branches of knowledge in the nineteenth century and contrasts the breadth of this knowledge with the limitation of a single mind and concludes that this creates a dilemma. Although the dilemma goes away once one abandons Schrödinger's faulty notion that there has to be some kind of universal knowledge that makes peace with the specialized knowledge accrued as a result of scientific advancement, Schrödinger, being also a philosopher, and a follower of Schopenhauer at that, cannot let go of the dilemma of his own creation. So, he finds himself obligated to address it:

I can see no other escape from this dilemma ... than that some of us should venture to embark on a synthesis of facts and theories, albeit with second-hand and incomplete knowledge of some of them -- and at the risk of making fools of ourselves.

This writer's earlier belief that the role of the physical apparatus can always be described by quantum mechanics ... implied that the collapse of the wave function takes place only when the observation is made by a living being [a conscious person] -- a being clearly outside the scope of our quantum mechanics. The argument which convinced me that quantum mechanics' validity has narrower limitations, that it is not applicable to the description of the detailed behavior of macroscopic bodies [such as a conscious person], is due to D. Zeh.

Wigner takes it back: The Wigner of the 1960s, who declared that it was not possible to formulate the laws of quantum mechanics without reference to consciousness, started to change his position in the 1970s. In a paper that he published in 1984, he wrote,

Weyl takes it back: On the fact that he shared the philosophical premise that postulated consciousness as the foundation of physical reality, Weyl said:

[I] was too prone to mix up mathematics with physical and philosophical speculation.