Sometimes dual use simply has charm. I'm fond of the "Combined Bingo Bag Kit and Seat Cushion," patented in 1992, and like to picture its inventor, Rebecca D. Harland, of New Bedford, Massachusetts, comfortable and organized at the parish hall. In 1869 Charles Singer, of South Bend, Indiana, gave us the Rocking Chair Fan, a contraption of bellows, bars and caning that offered a nicely ridiculous way of cooling off.
The New Catholic Encyclopedia says that Dualism is any theory that invokes two opposed and heterogeneous principles: Odd and Even, Good and Evil, Light and Dark, Mind and Body. We're well out of piano-violin territory here, but I think the appeal lies in the attempt to accommodate contraries that ring true to everyone. We all know, in our bones, about love-hate, about bittersweet.
How to square that, though, with Max Smart's shoe phone? It must mean something that "and" is one of the most ubiquitous words in the language.
I have a hard time disentangling dual use from coexistence from paradox. When Stephen Foster wrote "The sun so hot, I froze to death," did he become our dualistic patron saint? Would his songs have sounded just as good played on a piano-violin?
By Katharine Whittemore