“It’s not what you look at that matters. It’s what you see.”
While that is more of the medical or psychological explanation, I think we can agree that Thoreau is saying something much more philosophical in the quote above. It’s not just what enters your awareness; it’s how you choose to interpret what you see. Do you see the glass as being half-empty or half-full? Is this project beyond repair or is it a monumental opportunity?
We have to realize that reality is what we make it and there is always another way to look at exactly the same thing. Henry David Thoreau will be best remembered as an author and philosopher, but he will likely be known for his political views too. And these political views tie right back into our perception of reality.
For instance, his idea of “a better government” is one that “governs not at all.” Does this make him an anarchist or a proponent of personal liberty? You decide.