Niccolo Machiavelli used two words in his book, The Prince, to describe the factors that influenced events. In English these are virtue or character (virtu), fortune or chance (fortuna). Only virtue is internal – our nature – and although it manifests as voluntary action, it can only be somewhat, but not entirely controlled.*
The other – chance or fortune – can make the best-laid plans of mice and men go aft agley, as Robert Browning wrote, regardless of our efforts to the contrary.
In Chapter 25 of The Prince (What Fortune Can Effect In Human Affairs And How To Withstand Her), Machiavelli tried to explain why a leader with free will, with all the means, the desire and resources at his disposal would not always succeed in his endeavours. Virtue alone cannot always win. Luck – chance, fortune, randomness – often simply threw a monkey wrench into the gears.
Machiavelli describes fortune in two metaphors. First as a river that can overflow its banks, treacherously destroying the countryside. That river can be carefully managed by planning for the inevitable flood. Today we would call them worst-case scenarios:
I compare her to one of those raging rivers, which when in flood overflows the plains, sweeping away trees and buildings, bearing away the soil from place to place; everything flies before it, all yield to its violence, without being able in any way to withstand it; and yet, though its nature be such, it does not follow therefore that men, when the weather becomes fair, shall not make provision, both with defences and barriers, in such a manner that, rising again, the waters may pass away by canal, and their force be neither so unrestrained nor so dangerous. So it happens with fortune, who shows her power where valour has not prepared to resist her, and thither she turns her forces where she knows that barriers and defences have not been raised to constrain her.
Machiavelli is saying rather simply: plan for disaster. Prepare for the downturn, the recession, the changing politics, the loss of funding, the changing market. Have alternatives and contingencies ready. Don’t put all your eggs in one basket – for example, don’t base your budget or economic forecasts on the price of oil alone.