Nathan Seiberg

"Gravity is not an option in string theory. It is a logical consequence of it!"

"Most string theorists are very arrogant ... If there is something [beyond string theory], we will call it string theory."

"The quantum dualities, which are known as S-duality or U-duality, extend the classical T-duality and lead to a beautiful and coherent picture of stringy dualities. These exchange highly quantum situations with semiclassical backgrounds, exchange different branes, etc. As in the classical dualities, among all dual descriptions there is at most one description which is natural because it is semiclassical. All other dual descriptions are very quantum mechanical."

"Supersymmetry arises naturally in string theory. (It was originally motivated by string theory.)"

"Ultimately, we hope to find a fundamental theory that explains everything with no input parameters."

"Whenever you work on something and try to solve one problem, and you end up helping or solving many other problems, it is a sign that what you are doing is good."