Walden pondered

In “Walden,” Henry David Thoreau helped shape the way we think about nature and our place in the world. An American Icons segment examines why many readers think that Thoreau was a genius while others think he’s a hypocrite. A second American Icons segment remembers Leonard Bernstein’s “Young People’s Concerts” with the New York Philharmonic, which not only captured the genius and wit of the conductor but also showed the power of the then-young medium of television. And 40 years ago, Gloria Gaynor’s label released “I Will Survive” as a B-side, but it managed to become a hit — and an anthem.