There have always been two good sides to this disagreement, but neither side seems to wish to bend.

If someone feels more comfortable by using a book, I think it should be encouraged. Having a crutch might be necessary from some people who don't know the songs that well.   Also, given the average age of the people who attend song circles these days, having a cheat sheat isn't a bad idea for those who forget words.   I'd rather see someone with their face down in a book as opposed to someone with their face straining toward the sky trying to remember a line of a song.

At the same time, a person who uses a book should not feel upset if someone sings something other than one of the tunes in the collection. Some people mentioned that they have seen folks who seem lost when a new song is sung - which should not be a surprise. I find it incredible that someone would feel put off by a song not written in front of them.

A good song circle consists of many people. I don't think there should be a requirement either way - if you want to use a book, use it. If you prefer to sing a song from memory, you should do so.   The point of the event is to have a good time in the simple act of singing - and if you allow rules or ego to guide how the proceedings should go, you've created a situation that really is a clique and not a fun event.

Live and let live. Don't worry what the person sitting next to you is doing, and don't let your thoughts on how things should go dictate the enjoyment of others.