If you read through this growing list, you will see that people tend to discover that the most important invention in the last 2000 years is something they just happen to know a lot about. Well, I know a lot about some important inventions — like the codex book (and the consequent idea that a book can be a manual for living — that leads us to the 19th century and its dead ends) and like the computer (which gives us a model for ignoring the manual and just living by experiment), but I think it is quite undeniable that there is something far more important going on: effectual health care. Not just antibiotics, not just birth control, not just anesthesia (to say things mentioned here), but the underlying fundamental fact that we have learned to cross the scientific method with care for human beings and save lives. A thought experiment I like to have people play is this: review your own life and imagine what it would have been like without late 20th century health care. Would you still be alive today? An astonishingly large number of people get serious looks on their faces and admit they wouldn't: I wouldn't, that's for sure. It's medical techniques, it's antibiotics, but it's also vitamin pills and — in some ways most wondrously cost-effective of all — soap, as in the soap doctors use to wash their hands.