What is unforeseen is not necessarily something that was unknown, but rather was not predicted or anticipated. By contrast, what is unknown is ambiguous and a mystery, so it cannot be predicted or anticipated. We cannot do much about what is unknown, precisely because there is no way to quantify or understand it. The most we can hope to do is ‘manage’ the risks associated with the unforeseen, by anticipating those risks. Herein lies the distinction between risk and uncertainty. Risk can always be measured and generally understood, while uncertainty cannot be measured, and is the domain along the risk spectrum that paralyzes markets and causes bank runs.
We can learn a lot about this from the terrible tragedy of Germanwings Flight 9525, which was deliberately crashed into a mountain by the flight’s co-pilot, Andreas Lubitz, in 2015, killing all on board. The passengers and cargo had been successfully screened for explosives and weapons, which, ordinarily, would imply a safe and successful flight. Germanwings’ owner, Lufthansa, had learned during Lubitz’s Flight School training in 2009 that he had suffered from severe depression, and subsequently, that he had suicidal tendencies, yet it still allowed him to fly commercial aircraft.
It cannot be argued that there was not a potentially substantial risk associated with allowing Lubitz to fly. Such risk was neither unknown to the airline, nor could his action necessarily be considered unforeseen. On the contrary, that he was allowed to continue flying was probably criminally negligent, as the risk could certainly have been managed by preventing him from continuing to fly.
The simple mitigation strategy to this known risk, which was, ironically, compounded by the secured cockpit doors mandated post-9/11, would have been to conduct mental health screenings with greater scrutiny and frequency. Germanwings, Lufthansa, and the airline industry exposed the traveling public to the risk, however remote, that pilots would attempt to take their own lives along with everyone on board in aircraft.