We're running the most dangerous experiment in history right now, which is to see how much carbon dioxide the atmosphere... can handle before there is an environmental catastrophe.

Failure is an option here. If things are not failing, you are not innovating enough.

When something is important enough, you do it even if the odds are not in your favor.

People should pursue what they're passionate about. That will make them happier than pretty much anything else.

I think it is possible for ordinary people to choose to be extraordinary.

I'm extremely confident that solar will be at least a plurality of power, and most likely a majority... in less than 20 years.

Constantly seek criticism. A well thought out critique of what you're doing is as valuable as gold

Optimism, pessimism, f**k that; we're going to make it happen. As God is my bloody witness, I'm hell-bent on making it work.

I think that's the single best piece of advice: constantly think about how you could be doing things better and questioning yourself.

Mars is the only place in the solar system where it's possible for life to become multi-planetarian.

My mentality is that of a samurai. I would rather commit seppuku than fail.

You will never get to a new place by walking an old path.

What is interesting about you today, would not create new memory tomorrow braze up and create that envisage memory that is glaring you within.

No, not my spirit, just my ego, and my arms, and my chest, and my back, but luckily they are just bruised.” Squanto responded, “I fear you may not be so lucky.

My method is to take the utmost trouble to find the right thing to say and then to say it with the utmost levity.

I'm a real conservative. I never became a hippie, or a groupie. I never wore flowers in my hair.

It's not so much knowing when to speak, when to pause.

I want it absolutely clear when I stand before the judgement bar of God that I declared to the world, in the most straightforward language I could summon, that the Book of Mormon is true.

What is truth? A difficult question; but I have solved it for myself by saying that it is what the 'voice within' tells you.

When you are down and out something always turns up - and it is usually the noses of your friends.

I didn't know there was a dying-professor section at the bookstore.