Here is his brief summary of his book called "The Moral Landscape".
Morality and values depend on the existence of conscious minds — and specifically on the fact that such minds can experience various forms of well-being and suffering in this universe. Conscious minds and their states are natural phenomena, of course, fully constrained by the laws of Nature (whatever these turn out to be in the end). Therefore, there must be right and wrong answers to questions of morality and values that potentially fall within the purview of science. On this view, some people and cultures will be right (to a greater or lesser degree), and some will be wrong, with respect to what they deem important in life.
I posted this brief 20 minute preview of his ethos to provoke thought and I am pleased that a few are more interested in this topic than what a detroit style pizza is. I get the sense that in the minds of most on this forum, the question of "who will win the midterms?" is far more important than "can science define morality?".