English mathematician George Boole (1815–1864) was the first to develop ideas on symbolic logic, that is, the use of symbols to represent logical principles. He proposed this in his treatise, An Investigation of the Laws of Thought, on Which are Founded the Mathematical Theories of Logic and Probabilities, written in 1854. Today, this is called Boolean algebra. (For more information about Boole, see “Algebra”; for more information about symbolic logic, see “Foundations of Mathematics.”)