You do patent ideas, but the actual words written in a book describing that idea would only be protected by copyright at best. FWIW, the exact words describing the idea being patented are technically public domain; that's the whole point. You're free to go look up that patent, print it out, make whatever copies of it you want. Take any of the drawings in patents, put them on t-shirts, and sell them. No problem. Implementing the ideas those words represent is a different story.

For example, a patent describing a chemical process. The actual idea of how to do it is public domain, go look up the patent. Print it out. Do whatever with those words. Its fine. Building a plant to go do that chemical process to make that same output chemical in that same way, that's IP infringement. Its not the words, its the idea.