Should the word Boolean be capitalized?

I keep second guessing myself on this one.

On one hand it seems like it should because the word Boolean is derived from the name of George Boole, the inventor of Boolean logic. However, the term as it is commonly used is not meant to imply something is like George Boole in any way.

I suppose the same question could be asked for any technical term that is named for its inventor, for example Cartesian coordinate systems (René Descartes).

So the titular question stands; should I capitalize Boolean when using it to refer to 2 state logic or variables in a computer program?

By “…or variables in a computer program…” I don’t mean the actual code of a program. I meant in documentation that refers variables in a computer program.

For example “Implement a variable using the the Boolean data type for the particular programming language that you are using.”


Wikipedia capitalizes Boolean, as does Wiktionary (both as an adjective and as a noun). Merriam-Webster and the American Heritage Dictionary of the English Language capitalize the adjective and don’t have an entry for the noun.

What Wiktionary does not capitalize is the noun bool. M-W and AHD don’t have an entry for bool.

A search in the British National Corpus returns 94 cites for Boolean, but sadly only 50 randomly selected ones are displayed at a time, so I just hit “reload” a few times. The results that I got each time showed the following distribution:

Boolean 30 28 30 26
boolean 19 21 18 22
BOOLEAN  1  1  2  2

A search for bool did not return a single result.

Source : Link , Question Author : JohnFx , Answer Author : RegDwigнt

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