Peter Brook, possibly around the time he directed
Marat/Sade in the mid 1960s.

Quoth

Speaking of famous British director Peter Brook--as I will be in the course of reviewing of the North Coast Rep production of Marat/Sade in the Journal and later here--he makes a number of interesting comments and suggestions about various participants in the theatre process, including critics, in his book, The Empty Space. Here's one:

"The critic is part of the whole and whether he writes his notices fast or slow, short or long, is not really important. Has he an image of how a theatre could be in his community and is he revising this image around each experience he receives? How many critics see their job this way?"