The “Ben Franklin” is a decision making device who’s legitimacy rests on Ben’s fame and the authority of arithmetic.  You make two columns and in the first you enumerate the reasons for proceeding and in the other you enumerate the costs.  Finally you, presumably, sum up the two columns and make your decision.  This is all well and good until you discover that the same technique is prescribed as a good closing device for the saleman.

The advice to the closer is to pull out a sheet of paper; draw two columns and then fill in one column with all the reasons to buy the product.  You then hand the paper to your customer and invite him to fill in the second column.  The nominal reason why this approach works is that you, the salesman, will be well prepared for this pop quiz while the buyer won’t.  There is a secondary rational based on availablity; i.e. when you hand over the list your list of positive reasons will be close by while the objections won’t be.
I was reminded of this yesterday after reading a few papers upstream from a paper that Bruce Schneier pointed out.  The paper he pointed out The myth of the Superuser is an interesting and provocative paper; but I enjoyed more the work it rests upon, i.e. a body of work that attempt to dig into the puzzle of how people think about risk.  There are lots of amusing facts in that body of work; as well as a tremendous amount of posing.  Each paper is just like being handed the Ben Franklin by a salesman.
One of the fact’s I’d not noticed before says there is some experimental evidence that people are not able to treat the two columns as independent.  As you learn of benefits you tend to discount the risks and visa versa as you learn of risks you tend to discount the benefits.  Oh dear, the landscape we make decisions upon is ill-formed.  It is easier to push choices in some directions versus others.  If you try to push a decision, say to clarify it’s benefits, you running against the natural grain of the choice making surface.  You will have an easier time if at the same time you make a counter vailing points clarifying the risk.  If we visualize the choices as sitting on a x-y plane of risk v.s. benefit it is hard to move the discussion along the 45% line; and easy to move the perpendicular to that line.

our marbles roll naturally to into the gutters on one or another axis.    The Ben Franklin forces the decision onto this two dimensional plane.  That’s why it makes a great closing device.  We are good at making decisions and good at getting comfortable with them.  Time spent in the middle of that plain is a pain; and it’s more painful in it’s higher regions.  Specialists (technocrats, scientists, the thoughtful) who are skilled at surviving in the inner regions and high altitudes of this landscape are a pain in the neck for other people.
People, the literature reports, have a difficult time holding in their head options that are both high-risk and high-benefit.  Scenarios that feature that combination tend to be converted by the mind into something else.  Going into the war in Iraq is reasonable example.  The desired benefit was high and the risk was high.  The inability of individuals (and I presume it the same for groups) to hold in their head that extreme combination rapidly leads to polarized views of the situation.