It is often asserted that, in view of the situation in quantum theory, object and subject can no longer be sharply separated. 1 To use Heitler’s words, the ‘separation of the world into an “objective outside reality”, and “us”, the self-conscious onlookers, can no longer be maintained. Object and subject become inseparable from each other’. 2 This, according to Bohr, is due to ‘the impossibility of any sharp separation between the behaviour of atomic objects and the interaction with the measuring instruments which serve to define the conditions under which the phenomena appear’. 3 Heitler elaborates the point in some detail. ‘One may ask’, he writes, ‘if it is sufficient to carry out a measurement by a self-registering apparatus or whether the presence of an observer is required.’ And he arrives at the conclusion that the self-registering apparatus is insufficient, and that ‘the observer appears, as a necessary part of the whole structure, and in his full capacity as a conscious being’.

The word 'proof' should strictly only be used when we are dealing with deductive inferences.... Popper claimed that scientists only need to use deductive inferences.... So if a scientist is only interested in demonstrating that a given theory is false, she may be able to accomplish her goal without the use of inductive inferences.... When a scientist collects experimental data, her aim might be to show that a particular theory...is false. She will have to resort to inductive reasoning.... So Popper's attempt to show that science can get by without induction does not succeed.