Trust

Alfred North Whitehead famously said:

It is a profoundly erroneous truism, repeated by all copy-books and by eminent people when they are making speeches, that we should cultivate the habit of thinking of what we are doing. The precise opposite is the case. Civilization advances by extending the number of important operations which we can perform without thinking about them.

On a similar note, I would suggest that civilization advances not so much by increasing the level of personal trust amongst individuals (as argued in Francis Fukuyama's book Trust), but by increasing the number of situations in which personal trust is unnecessary. For further reading on this note, see Virginia Postrel's latest New York Times piece, "Should You Know Your Banker?"