Harold B. Lee – January, 1969 in the Improvement Era:
All that we teach in this church ought to be couched in the scriptures. It ought to be found in the scriptures. We ought to choose our texts from the scriptures. If we want to measure truth, we should measure it by the four standard works, regardless of who writes it. If it is not in the standard works, we may well assume that it is speculation, man’s own personal opinion; and if it contradicts what is in the scriptures, it is not true. This is the standard by which we measure all truth.
via LDSLastDays.com.