Rationality: What It Is, Why It Seems Scarce, Why It Matters by Steven Pinker is a top-level view of rationality as a concept. The explanations and examinations get rather technical, and the included graphs and charts are quite necessary.

Personally, I quite enjoyed this. I really like Pinker's style, and I've known that for a while. It makes an otherwise textbook-like book enjoyable instead of tolerable, at best. Pinker dives deeply into probabilities and statistics, specially those surrounding rational choices. 

The last two chapters of the book are the shining star of this book. They dive into why people make irrational or non-optimal choices, really break down the Monty Hall problem in a great way, and take a hard look at why humanity can collectively believe things like religion while being rational beings. 

From top to bottom, you'll have to be paying attention as you read this book, but if you're a fan of Pinker and his humor, enjoy some broad-strokes conversations about rationality, and don't mind following along with (or skimming over) some quite technical sections, this book is worth picking up.