According to Nassim Nicholas Taleb, predictions based on statistics would be reliable only if they drew their data from the future as well as the past. Here's how he illustrates his point:
"A turkey is fed for a thousand days by a butcher; every day confirms to its staff of analysts that butchers love turkeys 'with increased statistical confidence'.
"The butcher will keep feeding the turkey until a few days before Thanksgiving.
"Then comes that day when it is really not a very good idea to be a turkey."
As the author of The Black Swan warns in his spellbinding (but also exasperating) new book, Antifragile: Things That Gain from Disorder, "absence of evidence (of harm) should never be confused with evidence of absence".
But if prediction is beyond reach, predictability isn't, since fragility – the likelihood that something is going to break, whether it's a crystal cup or the US banking system before 2007 – is much easier to spot.
"Not seeing a tsunami or an economic event coming is excusable; building something fragile to them is not."
Taleb is famous for having recognised the fragility of the banking system early (The Black Swan was published in 2007) and then making a bundle on it when it fell apart. He's a natural teacher with a gift for metaphor.
In Antifragile, he focuses on systems that are not merely resistant to stress but in fact profit from it. The human body, for example, gets stronger with the stress of exercise and weaker with indolence.
An antifragile system, he emphasises, is not at all the same as one from which volatility has been removed:
"Small forest fires periodically cleanse the system of the most flammable material, so this does not have the opportunity to accumulate. Systematically preventing forest fires from taking place 'to be safe' makes the big one much worse.
"For similar reasons, stability is not good for the economy: firms become very weak during long periods of steady prosperity devoid of setbacks, and hidden vulnerabilities accumulate silently under the surface."
Though Taleb comes from the world of finance, in explaining how to invest 'antifragilely', he has produced a revelatory book on a bigger, deeper subject: wise decision making.
He writes so gracefully, with recourse to such clear and commonsense illustrations, that his ideas seem inevitable, almost obvious.
But Taleb admits that he's often "angry, dismissive and irascible". He's also preening.
While in time his ideas may be widely influential, as long as he offers no practical way to put them into large-scale practice in the financial system, they remain academic.
Available with free P&P on www.kennys.ie or by calling 091-709350.