When the first people started to argue against slavery, for example, this was a new idea. If you crowd-source, you'd never come up with this. And so the - exactly the kind of progress we've made couldn't be made if we depend it on crowd-sourcing.

And now having a child has been taken out of the sphere of biological determinism and placed instead in the domain of intentional action. Another option to consider and decide upon. And ... not to choose is to choose.

Math . . . music .. . starry nights . . . These are secular ways of achieving transcendence, of feeling lifted into a grand perspective. It's a sense of being awed by existence that almost obliterates the self. Religious people think of it as an essentially religious experience but it's not. It's an essentially human experience.

Philosophy addresses, in a systematic and progress-making way, questions of deep concern to everyone.

In fact, the answers that religion, as we have come to know it, provides to the question of human worth have played so dominant a role in the preceding centuries that believers often cannot conceive how non-believers can muster sufficient commitment to their own lives to get out of bed each morning, let alone the ethical wherewithal to regard others as deserving of moral regard. Once one "comes out" as an atheist, these are the inquisitions to which one is often subjected.

One of the interesting things about the ancient Greeks is that they really didn't have our conception of individual rights. They didn't have our conception of all lives matters. And it was really was true for them, that certain lives matter a lot more than others. It didn't dawn on them that all lives, although different, can be lives of equal mattering. And that is actually something a huge ethical lesson.

So Socrates was a kind of gadfly. He was a sort of philosophical urban gorilla hanging around in the middle of Athens, asking these peculiar questions of everybody - important people, young men, slaves - questions that had to do with ultimately what's the life that's worth living. And Plato was one of the young men who hung around him, a very aristocratic young man, came from a very old, important family.