We flatter ourselves into thinking that we live in a time of exceptional economic upheaval. The truth is that the present resembles the past. What we learned — and forget — is that a dynamic economy is inherently destructive. But the periodic convulsions often create long-term benefits. That has been true for most of our history.

To be sure, economic change now abounds: The internet; vast U.S. budget deficits; high private and public debt levels in both affluent and developing nations; the rise of China; growing income and wealth inequality; immigration; an aging population; "globalization" — not just trade in goods and services but huge cross-border money flows. And so on.

The very nature of the economy seems to be shifting, to what we do not know. Our sense of security is shaken. It's all true. But it's always been true. The same contradictory mix of awe and anxiety applies to most, if not all, previous economic eras. Indeed, by comparison to some, today's economy seems placid.