“And you are made of a hundred trillion cells. We are, each of us, a multitude.”

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.

If you wish to make an apple pie from scratch, you must first invent the universe.

The Earth is a very small stage in a vast cosmic arena.

Except in pure mathematics, nothing is known for certain (although much is certainly false).

Every kid starts out as a natural-born scientist, and then we beat it out of them. A few trickle through the system with their wonder and enthusiasm for science intact.

One of the greatest gifts adults can give – to their offspring and to their society – is to read to children.

In my experience most mathematicians are intellectually lazy and especially dislike reading experimental papers. He seemed to have very strong biological intuitions but unfortunately of negative sign.

It has yet to be shown by direct biochemical methods, as opposed to the indirect genetic evidence mentioned earlier, that the code is indeed a triplet code.

The inspired and expired air may be sometimes very useful, by condensing and cooling the blood that passeth through the lungs; I hold that the depuration of the blood in that passage, is not only one of the ordinary, but one of the principal uses of respiration.

Man comes not from an egg but from an animalcule that is found in male sperm.

For my part, I would say that the male sperm and seeds of plants have been penetrated so far that there is nothing further to discover in this great secret, but I could err in my opinion.

DNA was my only gold rush. I regarded DNA as worth a gold rush.

Religion is an attempt to get control over the sensory world, in which we are placed, by means of the wish-world, which we have developed inside us as a result of biological and psychological necessities. But it cannot achieve its end.

Biological men have no place in women’s sports.