The reason we form networks is because the benefits of a connected life outweigh the costs. It's to our advantage as individuals and a species to assemble ourselves in this fashion.

We will create life from inanimate compounds, and we will find life in space. But the life that should more immediately interest us lies between these extremes, in the middle range we all inhabit between our genes and our stars.

The social sciences offer equal promise for improving human welfare; our lives can be greatly improved through a deeper understanding of individual and collective behavior. But to realize this promise, the social sciences, like the natural sciences, need to match their institutional structures to today's intellectual challenges.

It used to be thought that our genes were historically immutable and that it was not possible to imagine a conversation between culture and genetics.

It's fashionable to speak about vulnerable populations in medicine and public policy, but it's harder to find a more vulnerable population than those who are dying.

It is the spread of the good things that vindicates the whole reason we live our lives in networks. If I was always violent to you or gave you germs, you would cut the ties to me and the network would disintegrate. In a deep and fundamental way, networks are connected to goodness, and goodness is required for networks to emerge and spread.

I like to have met someone in real life before being their Facebook friend.