Russians aren't perfect. Their politics are messed up, and they keep going through self-defeating economic cycles. But I have a lot of respect for Russia, and a lot of love for Russians.

Spaceflight isn't just about doing experiments, it's about an extension of human culture.

Our role is to develop techniques that allow us to provide emergency life-saving procedures to injured patients in an extreme, remote environment without the presence of a physician.

Don't let life randomly kick you into the adult you don't want to become

Almost everything worthwhile carries with it some sort of risk.

Decide in your heart of hearts what really excites and challenges you, and start moving your life in that direction

Every single day you're the result of what you did on the days prior.

Focus on the journey, not on arriving at a certain destination.

Remember, nobody changes the world on their own.

Every decision you make, from what you eat to what you do with your time tonight, turns you into who you are tomorrow and the day after that.

The cool things about space is when you put your pants on here, you can put them on two legs at a time.

Love sustains life.

If we feel inwardly strong, we will have no need or desire to speak ill of others.

My father looked as if I'd just gutted him - but it was mingled with a twisted sense of satisfaction. It felt good to hurt his feelings.

Day and night - ruthlessly apply key lessons of mankind such as leaving greed, fear and lust to improve the efficiency & effectiveness of life.

My sister wanted a cat for a pet... I wanted a dog, so they bought a cat and taught it to bark.

I love good food. I’m an epicurean, that’s for sure. … But I am not really a good cook.

We're going to have to do a whole lot more, and give nature at least a chance to repair some of the damage we've done.

Treating your adversary with respect is giving him an advantage to which he is not entitled.

We most often go astray on a well trodden and much frequented road.

I have found nothing half so good / As my long-planned half solitude, / Where I can sit up half the night / With some friend that has the wit.