Jonas Salk

The future is not a gift. It is an achievement.

The only limit to our realization of tomorrow will be our doubts of today.

The true sign of intelligence is not knowledge but imagination.

The greatest good is to live with purpose, to contribute to the well-being of others.

I am driven by the desire to alleviate suffering.

The greatest lesson I have learned is the importance of perseverance.

There is no patent. Could you patent the sun?

The greatest reward for a man's work is not what he gets for it, but what he becomes by it.

What we hope ever to do with ease, we must learn first to do with diligence.

Science is a way of thinking much more than it is a body of knowledge.

The most important question we can ask is, 'What is the next step?'

If we are to have a future, we must be willing to change.

I am not a scientist who happens to be a humanist. I am a humanist who happens to be a scientist.

The challenge of the future is to create a society that is both sustainable and humane.

We must be willing to let go of the life we have planned, so as to have the life that is waiting for us.

The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'

The only way to make sense out of change is to plunge into it, move with it, and join the dance.

The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.

We are all connected; to each other, biologically. To the earth, chemically. To the rest of the universe, atomically.

The greatest discovery is to find that a human being can change his life by changing his attitude.