There is, to be sure, a genuine problem in the phenomenon of quantum measurement, but I will not discuss it here. It concerns introspective systems, where subject = object so that the basic conception of a single subject observing an ensemble of objects must be modified.
- David Finkelstein, "The Physics of Logic"
(in "Paradigms and Paradoxes",ed. R.G.Colodny, 1971, p.60)