So… that one pictured above is my favorite, but here are four more I like a lot:

2. “Intellectual ‘work’ is misnamed; it is a pleasure, a dissipation, and is its own highest reward.” — Mark Twain

3. “Every calling is great when greatly pursued.” — Oliver Wendell Holmes

4. “I don’t like work, but I like what’s in work–the chance to find yourself. your own reality–for yourself, not others–which no other man can ever known.” — Joseph Conrad

5. “If I had eight hours to chop down a tree, I’d spend six sharpening my ax.” — Abraham Lincoln