Man, unlike any other thing organic or inorganic in the universe, grows beyond his work, walks up the stairs of his concepts, emerges ahead of his accomplishments.
– John Steinbeck
The Grapes of Wrath, Chapter 14. Steinbeck speaks of the need for humans to do something above and beyond a job of work. Their desire to build and create things is the spark that makes humans really come alive. Steinbeck is alluding to how Dust Bowl migrants are excluded, not only from jobs, but from being productive and creative members of society.