You know, I am so bad at tech that my daughter -- who is now 41 -- when she was five, was overheard by me to say to a friend of hers, If it doesn't bleed when you cut it, my daddy doesn't understand it. (Laughter) So, the assignment I've been given may be an insuperable obstacle for me, but I'm certainly going to try.

What have I heard during these last four days? This is my third visit to TED. One was to TEDMED, and one, as you've heard, was a regular TED two years ago. I've heard what I consider an extraordinary thing that I've only heard a little bit in the two previous TEDs, and what that is is an interweaving and an interlarding, an intermixing, of a sense of social responsibility in so many of the talks -- global responsibility, in fact, appealing to enlightened self-interest, but it goes far beyond enlightened self-interest. One of the most impressive things about what some, perhaps 10, of the speakers have been talking about is the realization, as you listen to them carefully, that they're not saying: Well, this is what we should do; this is what I would like you to do. It's: This is what I have done because I'm excited by it, because it's a wonderful thing, and it's done something for me and, of course, it's accomplished a great deal. It's the old concept, the real Greek concept, of philanthropy in its original sense: phil-anthropy: the love of humankind.

And the only explanation I can have for some of what you've been hearing in the last four days is that it arises, in fact, out of a form of love. And this gives me enormous hope. And hope, of course, is the topic that I'm supposed to be speaking about, which I'd completely forgotten about until I arrived. And when I did, I thought, well, I'd better look this word up in the dictionary. So, Sarah and I -- my wife -- walked over to the public library, which is four blocks away, on Pacific Street, and we got the OED, and we looked in there, and there are 14 definitions of hope, none of which really hits you between the eyes as being the appropriate one. And, of course, that makes sense, because hope is an abstract phenomenon; it's an abstract idea, it's not a concrete word.

Well, it reminds me a little bit of surgery. If there's one operation for a disease, you know it works. If there are 15 operations, you know that none of them work. And that's the way it is with definitions of words. If you have appendicitis, they take your appendix out, and you're cured. If you've got reflux oesophagitis, there are 15 procedures, and Joe Schmo does it one way and Will Blow does it another way, and none of them work, and that's the way it is with this word, hope. They all come down to the idea of an expectation of something good that is due to happen. And you know what I found out? The Indo-European root of the word hope is a stem, K-E-U -- we would spell it K-E-U; it's pronounced koy -- and it is the same root from which the word curve comes from. But what it means in the original Indo-European is a change in direction, going in a different way.

And I find that very interesting and very provocative, because what you've been hearing in the last couple of days is the sense of going in different directions: directions that are specific and unique to problems. There are different paradigms. You've heard that word several times in the last four days, and everyone's familiar with Kuhnian paradigms. So, when we think of hope now, we have to think of looking in other directions than we have been looking. There's another -- not definition, but description, of hope that has always appealed to me, and it was one by V