What I took away from this quote is that agreement where there has not been the freedom to question is not really agreement.
We see this all the time in American churches. Many congregants believe their positions to be "bullet proof" correct, yet cannot give an account of why they believe this way. It is not a position they came through by their own discoveries and wrestlings, rather it was imparted. And because many churches hold a tacit agreement within the congregation to peaceably hold to these views, it never occurs to the congregants to think that there might be other possibilities.
This also presents a problem in leadership. In 27 years of Christianity, I have heard many Pastors and leaders state something like this:
"I feel such and so about topic X...... but I could never tell my congregation that".
This is the harmony that the author seems to feel is lacking.
As a personal example: I was taught the penal substitutionary view of atonement; not amidst other views and theories... that was the only option. It was not until much later in my Christianity that I learned that many Christian groups have NEVER accepted that view. So, I didn't really "believe" that position... it was simply the only one I had been taught. My agreement with my fellow parishioners on this issue wasn't really agreement, we simply knew no differently.