This you may say of man – when theories change and crash, when schools, philosophies, when narrow dark alleys of thought, national, religious, economic, grow and disintegrate, man reaches, stumbles forward, painfully, mistakenly sometimes. Having stepped forward, he may slip back, but only half a step, never the full step back. This you may say and know it and know it.
– John Steinbeck
The Grapes of Wrath, Chapter 14. This is Steinbeck’s affirmation of the potential of human beings, as he talks about the inevitability of progress and change. When change happens and mankind moves a step forward, there is no returning back to the way things were. It is a message of hope for the dispossessed and migrants struggling during the Great Depression.