Jonas Salk

The greatest tragedy in life is not death, but what we let die inside of us while we live.

To be fully alive, fully human, and fully aware is to be in a constant state of wonder.

The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it.

The human race has one really effective weapon, and that is laughter.

There is no such thing as a perfect vaccine, just as there is no such thing as a perfect anything. The goal is to make the best possible vaccine, and then to improve upon it.

What is the most important thing in life? To be useful to others.

I have no doubt that the vaccine will work. The question is, how well?

Which is more important, the individual or the species? The individual is important only as a means to the end of the species.

Science is a human endeavor, and like all human endeavors, it is subject to error.

I am not a hero. I am just a scientist who did his job.

The greatest challenge of the 21st century will be to learn how to live together on this planet.

The important thing is not to stop questioning. Curiosity has its own reason for existence.

The measure of intelligence is the ability to change.

Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution.

I don't think of myself as a savior. I think of myself as a human being who is trying to do his best.

The greatest challenge is to find a way to live in harmony with nature.

The greatest discovery is to find out that you can do anything.

The most important thing is to keep learning, to keep asking questions, to never be satisfied with what you know.

The greatest gift you can give to others is the gift of your presence.

The greatest good is to be useful to others.