If people are allowed and encouraged to think for themselves, they can come up with some amazing ideas. Kline has, over several years, developed a "Thinking Environment" to enable just that. It is stunningly simple, yet apparently very effective: don't interrupt, give everyone a turn, find the blocking assumptions, ask Incisive Questions: "if you knew that [freeing assumption, opposite of blocking assumption], how would you [achieve your goal]?". There's more in the details, of course, but essentially the ideas is to let the other person think, by listening to them, and not leaping in with ideas of your own, paraphrases, or dismissive putdowns.
The book describes how the process works for thinking in a group, and in the Thinking Partnership (thinking in pairs). It describes how it can work in a variety of situations, from business meetings to family decision-making. And it gives detailed examples of it working in practice.
In essence, this is another "treat people with respect and assume they are competent human beings" books, with details of precisely how to do that. It's depressing that we need so many such books. Given we do, this is a worthwhile addition to the collection.