History of the War in Spain and Portugal, from 1807 to 1814 Book

This is the only "history" book I am aware of that follows lines of thought through history, rather than an individual person or invention.

This is the proverbial butterfly fluttering its wings in the 12th century, leading to cell phone technology today.

The book can be a bit disconcerting to read, since you can read it in any order you like. This is a unique experience in my book-reading life, and the first time I read this book I read it front to back.

Later I went back and followed particular threads of thought through the book. You read a paragraph on something, and it mentions something else interesting. You can either continue reading in a linear manner, or jump to the "link" to the other thing.

In this way, you can jump back and forth throughout the book, chasing a single line of thought through history.

Amazing book...