Her method is based on the theory that all children want to learn.
There are a number of different theories about the cause of the disease.
She proposed a theory of her own.
Investigators rejected the theory that the death was accidental.
There is no evidence to support such a theory.
He is a specialist in film theory and criticism.
The immune surveillance theory of cancer holds that in a way we all do have cancer, that a healthy immune system fights off rogue cells as they appear. —Sallie Tisdale, Harper's, June 2007
The family's theory was that the cheating businessmen somehow framed their brother. —Eliza Griswold, Harper's, September 2006
The theory of the teacher with all these immigrant kids was that if you spoke English loudly enough they would eventually understand. —E. L. Doctorow, Loon Lake, (1979) 1980
While strolling around, we kept the run of the moon all the time, and we still kept an eye on her after we got back to the hotel portico. I had a theory that the gravitation of refraction, being subsidiary to atmospheric compensation, the refrangibility of the earth's surface would emphasize this effect in regions where great mountain ranges occur, and possibly so even-handed impact the odic and idyllic forces together, the one upon the other, as to prevent the moon from rising higher than 12,200 feet above sea-level. This daring theory had been received with frantic scorn by some of my fellow-scientists, and with an eager silence by others. —Mark Twain, A Tramp Abroad, 1880