We have never had to say no (at least so far; son is 17). We talk everything out with our son. If we had concerns, we would voice them. We would ask what he thinks/ how he feels. He is a very reasonable person. Given the respect he deserves for his own thought process, he always has come to conclusions we respect and can endorse.
I extend the concept of respect for children to other than my own as well. As an elementary school principal, I remember a conversation I had with the recess aides in which I remarked that “because I said so” is not an acceptable response to a child’s question about a directive. In a real emergency, it would be okay to say, “I will explain to you later but you need to do this now for safety”… and then get back to the child later with the explanation. Barring an emergency, share your reasoning! And when kids got in trouble and were sent to me for some sort of misbehavior, I would always have them reason out what they had wanted, why their choice worked out badly in how it affected themselves or others, and what they would do differently next time they were in a similar situation.
The way I see it, we are preparing children for independent thought and reasoning and decision making. My husband and I do not believe in the concept of blind obedience. How many terrible things have been done in history by people who believed in “just following orders” and committed crimes in war and elsewhere, or thought that a deity was calling upon them to ostracize or murder the innocent? Being responsible for one’s own decisions and actions is important.
That does not mean it is wrong for a parent to say no or that such an action will lead to something bad. At times, a parent may need to say no. But the manner of saying it is important. It always should be conversational and respectful, in whatever manner is appropriate for the child’s age/ development/ mental capacity.
And a parent should be open to being convinced by their child; sometimes, parents will say they said no reflexively and then regretted it but felt they needed to “follow through.” Why not just say, “I thought about it, and you’re right?”
A couple of other points in response to posts above: coming to chaperone your small child while he is swimming is not “saying no”… the child still gets to go to the party, but you are ensuring his safety. My child did not swim unsupervised until he was a teenager, and no parent ever objected to our staying at a party (in fact, most of his friends’ parents also stayed). This was never an argument; our son understood our reasoning and agreed with it.
And when they get older, having trust in them and having open communication is important. I remember one Halloween in middle school when my son came home and said that one friend had brought shaving cream and toilet paper, but that my son and then all the other friends said, “No way.” He was comfortable making his own decision, others followed him, and he was also comfortable telling us about it afterwards. That type of conversation helps a child process his decision making and reinforces his process. My hope is that he will carry this type of independent reasoning and decision making into other situations in the future, where alcohol or other drugs or hazing or other potential dangers are involved. And that when he makes decisions along the way and afterwards is unhappy with the outcome or thinks they were mistakes, hopefully he will process those as well and learn from them.
In short, supervision is part of parenting. But the best supervision also develops the child’s capability to make his or her own decisions.