".. the second theme: appeal to the concept of objective knowledge in arguments which purport to dispose of it. Even the enemies of objectivity rely on it." (P 214a)

"The experiment makes no sense and establishes nothing about the influence of non-perceptual factors on perception unless there is an objective fact of the matter as to how the objects appeared to the participants and what their true lengths were. ... Once again the critics of objectivity must rely on it for their arguments." (P 215ab)

"Speaking generally, one cannot present an example of investigator bias without also presenting the objective fact that the investigator has missed. ... All such instances self-destruct in the same way." (P 217b)

"As usual, skepticism defeats itself. There can't be evidence that all investigation is biased." (P 221a)