My colleague Joe Kimble has attempted to refute the common superstition against beginning a sentence with the word "but."
According to Kimble in Lifting the Fog of Legalese, the word 'but' is "far more common and more deft than 'however' to show contrast at the beginning of a sentence.”
Others have rightly pointed out that, rather than being incorrect or too informal for legal writing, "but" is sometimes the best way to start a sentence.
How far can the battle against this superstition be carried? Is it ever proper English to begin a paragraph with "but?" An entire chapter? My quick survey has produced an example of each, both by noted writers.
No less an authority on language, Bryan Garner began a paragraph with But in the Scribes Journal of Legal Writing (vol. 3, p. 91):
But (some might say) we’re talking here about formal legal writing, not newspapers!
And Stephen Ambrose, no slouch of a writer, began a chapter in his 2001 book The Wild Blue (p. 225):
But the approaching end of winter brought little improvement in the weather.
As these professional writers illustrate, it is not necessarily poor form to use "but" to begin a sentence, a paragraph, or even a book chapter. Is that as far as the point can be pursued? Is it possible that an entire book beginning with "but" is out there somewhere? Or a book title?
A brief search turned up a music album by Phil Collins titled But Seriously, and an R-rated movie But I’m a Cheerleader (“A comedy of sexual disorientation”). I even found a couple of children’s book titles beginning with "but:" But It’s Not My Fault and But No Elephants. I could not, however, locate a serious book of nonfiction with a title beginning with "but." If you find one, please let me know.
Postscript: In 2017, several years after this piece was first published, tennis great John McEnroe borrowed Phil Collins’ album title for his book, But Seriously. And so now another frontier has been crossed.