We all have to trust one another. That is to say, we are put in a position of having to trust one another just in order to live.

I think of it most acutely when I get on an airplane, though it’s always true. As I buckle in and hear the engines rev, I always wonder about the mechanic who serviced the aircraft — perhaps on a Monday morning, with a hangover, after an unfinished argument with the wife, or harboring a grievance with the airline.

I have no choice; I need to get to Atlanta.

Not just individuals but corporate entities have to do some trusting. One of France’s largest banks, Société Général, trusted a 31-year-old trader and he cost them $7.2 billion for their confidence a month ago.

Our own banks, which borrow as much as 90% of every dollar they invest, trust that the borrowed money is good. At least they used to.

Some acts of trust are based on better assumptions than others — but all trust is based on assumptions. Till recently banks’ assumptions were that housing prices would keep rising, and that computer-generated evaluations of the markets were infallible.

My own personal assumption is that the God of the Bible backs up his Word.