“The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.”

All civilizations become either spacefaring or extinct.

If we continue to accumulate only power and not wisdom, we will surely destroy ourselves.

Across the sea of space, the stars are other suns.

You are worth about 3 dollars worth in chemicals.

We live on a mote of dust suspended in a sunbeam.

We can judge our progress by the courage of our questions and the depth of our answers, our willingness to embrace what is true rather than what feels good.

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.

The visions we offer our children shape the future.

Nature is unsentimental. Death is built in.

We are star stuff which has taken its destiny into its own hands.

Not explaining science seems to me perverse. When you’re in love, you want to tell the world.

Not all birds can fly. What separates the flyers from the walkers is the ability to take off.

Nature is always more subtle, more intricate, more elegant than what we are able to imagine.

When we look up at night and view the stars, everything we see is shinning because of distant nuclear fusion.

Imagination will often carry us to worlds that never were, but without it we go nowhere.

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.

The brains -the thinking organs- are the world producers -nature’s genitals.

I was an ambitious child and I tended to be scatterbrained. If I was at school and saw a bird outside the window I wanted to follow it. I was adventurous.

Remember the mind is your best muscle, BIG ARMS can move rocks, but BIG WORDS can move mountains. Ride the brain train for success.

Working out is incredibly boring. I swear it’s true that the bigger your muscles get, the fewer brain cells you have.

Some songs are just like tattoos for your brain… you hear them and they’re affixed to you.

Unlike any other nation, here the people rule, and their will is the supreme law. It is sometimes sneeringly said by those who do not like free government, that here we count heads. True, heads are counted, but brains also.

My IQ is somewhere between Spiro Agnew’s and Albert Einstein’s.

The first virtue of a young man today – that is, for the next fifty years perhaps, as long as we live in fear, and religion has regained its powers – is to be incapable of enthusiasm and not to have much in the way of brains.