Well, for much of this century, the source of optimism was found in the collectivist philosophy of life rather than in the individualistic philosophy of life. In economics, we call it socialism. In politics, we call it communism. These philosophies would not be part of the free market concept as we know it. Now collectivism is shattered.
Individualism is in.
And collectivism is not coming back as a force, so the taproot for that kind of optimism has been severed. Interestingly enough, I was ordained in the middle of the 20th century, in 1950. I have always been an optimist, a strong believer of the power of the human being to become what he wants to become to change the world. History is never shaped by collective masses. History is always shaped by an individual who has a dream, goes for it, and is prepared to die for it.