When asked how he persisted despite 10,000 failures, Edison reportedly answered; "I have not failed 10,000 times. I have not failed once. I have succeeded in proving that those 10,000 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."He was a Popperian falsificationist before his time.
And a freethinker, as Jennifer Hecht has documented in Doubt: A History and here:
In 1910 Thomas Edison was asked by the New York Times if he thought it possible to communicate with the dead. “No,” he responded, “all this talk of an existence for us, as individuals, beyond the grave is wrong. It is born of our tenacity of life—our desire to go on living—our dread of coming to an end as individuals. I do not dread it though. Personally, I cannot see any use of a future life.”
A public figure in 1910, she notes, could still speak in public of a "rationalist, naturalist understanding of humanity and the universe." When's the last time you heard someone of Edison's stature (but who would that be, now?) say anything like this?
Hecht blames the Cold War and its aftermath. That's a big part of it. So is the stultifying tendency of tradition, almost every tradition, to discourage intellectual honesty. But the tradition of doubt itself stands as a shining exception. You should read the book, it's good.
And read her latest, a heroic response to the epidemic of suicide called Stay. It too is a testament to perseverence.