Again, the authority of parents, though the deference it begets remains to grace the relations of parents and child, is itself a provisional function, and is only successful as it encourages the autonomy, if we may call it so, of the child. A single decision made by the parents which the child is, or should be, capable of making for itself, is an encroachment on the rights of the child, and a transgression on the part of the parents......
Authority has an equivocal meaning nowadays, of course, as it did in CM's time. This is probably why she discusses it in such depth in her books. It is something inherent in the role of parent that is for the benefit of the child. It is NOT a merit badge, proclaiming that the parents are superior to the children. As CM points out, how could that be when in many ways our task as adults is to "become like little children?"
It is NOT meant to be something the child is meant to "knuckle under" to; in other words, it's not a WMD in the parent/child struggle for power. Yikes! Of course, the immature child may sometimes see it that way, but if the parent uses it in that manner, it usually works against authority rather than for it.
Rather, it is the means by which the child is "brought up" (CM used that homely Anglo-Saxon term, she said, to imply both the parental effort involved AND the direction in which the efforts ought to go) to be able to take over the reins for himself. Authority does not mean a right to exploit someone or jerk them this way and that, but the duty to nourish someone else's freedom and help them to become worthy of it.
The word "autonomy", too, is often misused in her time and ours, which is probably why she put it in italics with a qualifier. Autonomy is owed to the individual in the sense that a human being must never be used for the purposes of someone else. But autonomy is not anarchy; it is what the Pope called "freedom for excellence". And it exists in relation to other people; it is not simple individualism.
I was trying to write out a bit more, but it's surprisingly difficult. I'll probably have to try to approach it a different way some other time.