Who said "The obligation is clear: it is to act."?

This quote is attributed to Jonas Salk.

The obligation is clear: it is to act. - Jonas Salk

"The obligation is clear: it is to act."

Jonas Salk Motivation

Virologist and Immunologist American 1914–1995

"The reward for work well done is the opportunity to do more."

"Life is an adventure in forgiveness."

"Hope lies in dreams, in imagination, in the courage of those who dare to try."

"Our greatest responsibility is to be good ancestors."

"I believe in working hard for what you want."

"Never underestimate the power of determination."

"I don't need a reason to fight."

"The most important thing is the mission. Nothing else matters."