Shady Characters, by Keith Houston, is a history of marks and punctuation that accompany text, from the familiar (e.g., quotation marks, the “at” and “pound” signs @ and #) to the largely hidden or no longer used (pilcrow ¶, manicule ☚).

I think this book was recommended to me on Twitter (by Lindsay Blackwell?) when I was really looking for something else. For nearly 25 years now I’ve been interested in the history and consequences of mathematical notation. Does the way in which physics, say, is expressed mathematically (by which I mean notationally) affect how physicists think about the world and, consequently, what new ideas emerge from that thought?

For instance, vector calculus is at the heart of physics and it can be expressed in both subscript and operator notation (google “vector calculus notation” and poke around). They’re very different ways to express the same thing. In subscript notation even fairly simple ideas get messy in a hurry, while in operator notation complex ideas can be beautifully and elegantly expressed.

I could be wrong, but I think a teacher once told me that subscript notation came first. Perhaps operator notation was a big breakthrough. I imagine that there could be things that are so messy to express and manipulate in subscript notation that it actually impeded thinking in some important ways. Maybe operator notation was a hugely consequential innovation not just in how physics is written but in how it is perceived by the mind of the physicist. If so, that’s the book I want to read.

Anyway, Shady Characters isn’t about that, but it comes somewhat close. In parts it conveys how language was written and adorned with notation that aided or impeded comprehension. In turn, I imagine, actual ideas were variously suppressed or promoted merely because of font, word spacing, and other adornments.

IT’SHARDTOBELIVEIDEASWEREONCEEXPRESSEDLIKETHIS. And yet, take a look at Twitter and you’ll see more or less just that in hashtags (#icantbelievepeoplewritethisway). That’s got to matter in whether and how people engage with ideas. Shady Characters didn’t really get into this in depth, but that it provoked the idea while providing a fairly interesting history of punctuation and symbols of expression makes it worthwhile.

(Note: It sucks a little as a Kindle book. A lot of the symbols are illustrated with tiny images that just don’t work in Kindle. It’s still mostly readable, and it’s how I read it. But, come on, it’s 2015. Amazon should be ashamed.)