"Because there is a law such as gravity, the universe can and will create itself from nothing," he writes. "Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist.So goes the quotation of Stephen Hawking in the Guardian (U.K.) in a story about the impending release of "The Grand Design" by Stephen Hawking and Leonard Mlodinow.
The statement from Hawking as it stands is self-contradictory, though certainly Hawking might end up explaining it away in his book as only an apparent contradiction.
Why is the already oft-quoted blurb self-contradictory?
It's a bit obvious. The statement "Because there is a law such as gravity" implies that gravity is something. The subsequent statement, "the universe can and will create itself from nothing" implies (very directly and in so many words) that the universe can create itself from nothing. But the second statement appears contingent on the first. So, pending Hawking's explanation, we're being asked to either believe that gravity is the nothing (or at least the contingently necessary nothing, to wax philosophical) out of which the universe is created or else we are to believe in gravity was created along with the rest of the universe yet explains how the universe came from nothing.
Gravity cannot be both something and ~(not)something at the same time and in the same sense. That is contradictory.
Hawking deserves every chance to explain himself. But don't give him the benefit of the doubt just because he's a genius. Even the brightest among us are prone to errors of thought.