"We did not have a university education, but we had a good deal of common sense."

"I know of only one bird — the parrot — that talks; and it can't fly very high."

"The greatest obstacle to progress is not ignorance, but the illusion of knowledge."

"I confess that in 1901 I said to my brother Orville that man would not fly for 50 years. Ever since I have distrusted myself and trusted him."

"We did not find it necessary to use any of the formulas of the scientists, but we worked out our own formulas."