"... I am going to go out on a limb, and argue that"

“We believe string theory has a set of solutions, some of which might describe our world. Even leaving aside the question of few vacua or many, and organizing principles, perhaps the most basic question about the landscape is whether it will turn out to be more like mathematics, or more like chemistry.”

“Superstring theory has been studied intensively since 1984, when the discovery of Green and Schwarz of anomaly cancellation convinced many physicists that it provides a consisten theory of perturbative quantum gravity, gauge interactions and chiral matter. The basic difficulties in quantizing general relativity and supergravity are visible at low order in the loop expanison, while superstring theory was shown to be well-defined and finite to all orders.”