The spren felt very natural to me. I didn’t anticipate them being as controversial as they’ve become. I think part of the reason for this is that the people of the world take them as natural. They’re just there, and everybody in this world is going to treat them as familiar. Asking them why a spren appears the way it does is a little like asking a layman in our world why sometimes the wind blows and sometimes it doesn’t. If you walk outside, sometimes the wind will be blowing and sometimes it won’t, and you just take that for granted. You don’t ask why, you just say that it’s windy or it’s not windy. These characters in this world will say, “Oh, there are some fearspren; someone’s scared,” but sometimes they don’t appear and sometimes they do. Some of the rationale around that will become more and more clear as the series progresses, but the reason it’s not explained in this book is because the characters have just all grown up with these things all their lives. They don’t necessarily ask those questions any more than most of us ask why a particular leaf falls off a branch when another one stays attached. It’s just the natural process of the world. There are lots of reasons why they’re there, but I don’t think I can get into those without spoiling the series.
You will find out much more about the spren as the series goes on. There are a lot of things that get spren where the spren are not noticeable, or they only occur in very rare circumstances or in certain regions, as Axies explains. So the phrase “There’s a spren for that” that I’ve seen popping around on the internet is actually fairly accurate. There’s a spren for quite a lot of things. I don’t want to delve too deeply into this until I’ve written more in the series and you begin to understand exactly what the spren are.