Coping, deciding and managing with unknowns does not boil down to getting rid of them. The two favorite ways of managing unknowns in Western culture are reduction (e.g., through research) and banishment (e.g., through bureaucratization). Other approaches are available that are more viable when unknowns are irreducible or cannot be banished without incurring unacceptable consequences. Two chapters of the Bammer-Smithson book review these concepts and survey ways of managing with unknowns, including irreducible unknowns (Bammer & Smithson, 2008: Ch25-26).

In the second chapter of my 1989 book (Smithson, 1989, Ch2), I present some basic arguments against the pursuit of full certainty.  There, I draw on illustrations from structural engineering and jurisprudence.  But my favorite case in point is reserved for the end of that chapter, namely the logicist program in mathematics during the early part of the 20th century.  Most people think of mathematics as possessing absolute certainty, so it's ironic that mathematicians were among the first disciplines to recognize that it contains irreducible unknowns (paradoxes and undecidables).

At the heart of the reduction-banishment impulses are a couple of important intuitions. The first is that if we use a well-reasoned, evidence-based approach to making decisions under uncertainty then we’ll make the right decision most of the time.  The second is that the remedy for error-prone decision-making tools is to make them more accurate. These intuitions are not always right, and I've presented an example of how they can go wrong here.

Can there be such a thing as a good decision-making method under ignorance? What criteria or guidelines make sense for decision making when we know next to nothing?  I've written two pieces about this since the 2008 book. One of them is autobiographical, taking up the theme that we can’t plan the future by the past. It charts the decision-making by my brothers and me regarding our elderly parents' care.
The second is a more frontal attack on the question of what prescriptions are available for making decisions when so little is known that current rational frameworks stand silent. My colleague Yakov Ben-Haim and I had a paper published developing the ideas in this piece considerably further.