Boole's "Laws of Thought"

I've been in the mood to dig a bit deeper into the past of mathematics and logic and philosophy. So I've taken a break from the early twentieth-century Russell and Wittgenstein to take a look at the origins of pure mathematics and logic—in George Boole's 1854 treatise "An Investigation of the Laws of Thought, On Which are Founded the Mathematical Theories of Logic and Probabilities."

A fully TeXed version is available free of charge from the Gutenberg Project.

It's exciting to read the genesis of Boolean logic here:

 "... instead of determining the measure of formal agreement of the
 symbols of Logic with those of Number generally, it is more
 immediately suggested to us to compare them with symbols of quantity
 admitting only of the values 0 and 1. Let us conceive, then, of an
 Algebra in which the symbols x, y, z etc. admit indifferently of the
 values 0 and 1, and of these values alone."

from Chapter 2, "Signs and their Laws"

Fascinating stuff.