Compose or comprise?

“Comprise” is a frequently misused word, a common accessory to the sin of pretentiousness. People want to sound high class, so they write “is comprised of” when they mean “is composed of” or even plain old “composes.”

I ran into an article in The New York Times online that presented them with a wonderful opportunity to be pretentious, and they didn’t take it! Hooray (for once) for The New York Times! here’s what they said, and it’s correct:

The project follows the successful effort by a group at the museum to replicate a far less complicated Babbage invention: the Difference Engine No. 2, a calculating machine composed of roughly 8,000 mechanical components assembled with a watchmaker’s precision.

The machine is composed of parts! Yesss!

Now that is a construction in the passive voice. What if they had wanted to use the active voice? Then they would have written:

The project follows the successful effort by a group at the museum to replicate a far less complicated Babbage invention: the Difference Engine No. 2, a calculating machine comprising roughly 8,000 mechanical components assembled with a watchmaker’s precision.

Now “comprise” is appropriate.

Never ever say “…is comprised of…” Ever! Unless you’re showing someone what not to do. Harrumpf.

Here’s a picture of the difference engine.

The machine is about eight feet tall. That's a picture of Charles Babbage on the wall.