9 of history's greatest philosophers reveal the secret to happiness

A well-stocked Netflix queue can go a long way toward pure and utter happiness, but sometimes there's still something missing.

For those moments, it can help to fall back on the wisdom of history's greatest thinkers: Kierkegaard, Socrates, Thoreau, and Confucius.

Here's what philosophers discovered about happiness long before orange became the new black.

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