If I have seen further than others, it is by standing upon the shoulders of giants.
~Sir Isaac Newton
There are two kinds of visionaries.
The first type sees farther, like Sir Isaac Newton. They possess a special gift of brilliance, genius, or perception. They see what others cannot, recognize mysteries that hide in plain sight, uncover beauty and order where the rest of us see only chaos. For the most part, they are born, not made.
Then there are those who are blessed not so much with the ability to see, but with the ability to bestow vision, to illuminate the world not with new insights but by giving the gift of insight to others. It is not their acumen, but rather their irrepressible pursuit of transcendence that inspires us to do as much with our lives as they have done with theirs.
Thirty-six years after becoming the first man in orbit, John Glenn became the oldest man in space, not as an ego trip or publicity stunt but to observe the effects of weightlessness on his 77-year-old body. As with his first trip, he showed that the limits upon human beings are mostly self-imposed.
Most of all, he showed us not only what a person can do, but what a person should be.