"You lose a sense of the amounts when you're doing this kind of job," the rogue trader Jérôme Kerviel told Agence France-Presse this week. "Everything gets dematerialised. You can get carried away."
It is possible Mr Kerviel was just using the interview to set up his legal defence. French authorities have accused him, after all, of forgery and breach of trust.
Mr Kerviel had risen from the back office at Société Générale to become a "warrant arbitragist". His job was running pairs of complementary positions, the one hedging the other. Mr Kerviel allegedly used his knowledge of middle-office security procedures to fabricate hedges. He thereby disguised risky speculations as safe arbitrage - resulting in a collapsing position of EU50bn ($72bn) that it took his employers three days and EU6.3bn to unravel.
But in speaking of dematerialisation and getting carried away, and in plausibly claiming that "enrichissement personnel" was the furthest thing from his mind, Mr Kerviel may actually have identified better than anyone to date what is so unsettling about the debacle in which he is the central figure.
There has been a strong populist tinge to much of the commentary, which has focused on greed and on the mathematical complexity of the structured equity derivatives business that Société Générale can claim to have pioneered. Casino capitalism has been invoked and Mr Kerviel has been lionised on French blogs as its saboteur (if an unwitting one). It has even been suggested that Société Générale winked at Mr Kerviel's misdeeds as long as they were remunerative - a dubious theory.
Mr Kerviel's behaviour reveals problems not just in modern capital markets, but in modern society. In an age of technological sophistication, the ability of a single stubborn person to muck up a system has increased dangerously.
Earlier this decade, the US columnist Thomas Friedman made this point forcefully in the context of terrorism, charting the rise of what he called the "super-empowered" individual. Mr Friedman meant someone who can single-handedly acquire, build or use mighty military weaponry. Mr Kerviel's actions show that a super-empowered individual can get his hands on destructive financial weaponry, too.
As someone told the FT this week: "What is striking here is the contrast between the mediocrity of the trader and the scale of the catastrophe."
The report on the Kerviel affair released on Monday by Christine Lagarde, France's finance minister, addressed this problem not in terms of empowerment but by drawing a distinction between gross and net exposure.
"Monitoring of deals today is focused on the net amounts of [investment] positions, which allows us to assess market risk," the report ran. "Heightened attention must also be paid to gross amounts, which reflect the degree of an establishment's liability [engagement]." This new preoccupation with gross liability reflects a widespread unease about little traders with big portfolios.
Mr Kerviel knew the ways of the back and middle office inside-out, from senior traders' passwords to the time of night when accounts were reconciled. He allegedly used all sorts of stratagems to avoid detection - forged e-mails, internal counterparties that allowed him to avoid margin calls, transactions marked "pending" to avoid immediate reconciliation and so on. He claimed that other traders had done the same, albeit "at a lower level". While this allegation, if true, would not exonerate Mr Kerviel, it is disturbing.
There has been a lot of talk in recent weeks about the especial laxity of Société Générale's monitoring of its traders. As one trader told Les Echos: "They were running a Ferrari with Citroën brakes." This has the ring of after-the-fact tut-tutting. Société Générale's system seems to have worked perfectly well at curbing irresponsibility in its star traders - but it did not work to curb the irresponsibility of a middling trader who knew how to get around the system. Why not?
The stars of the trading floor resemble the stars of professional sports. In both walks of life, there are a lot of "intangibles" - it is hard to break down the relevant gifts that go into making a superior performer. Sometimes you see a basketball player, with a clear path to an easy basket, attempt an absurdly elaborate reverse slam-dunk and miss. Coaches used to bench players for this kind of indiscipline. They do not any more, because they understand something about human nature.
Sport looks like a practical job, built around the accumulation of points. But inside players' heads, sport is a heroic succession of brilliant stunts. It resembles a dream. That dream is a mighty force. The frame of mind that leads a player idiotically to mess up an easy basket is the same frame of mind that allows him to make 10 consecutive three-pointers as if he is in a trance. Coaches indulge their players because they sense that harnessed fantasy is often more practical than practicality.
Like athletes, traders tend to go for the gold, to follow their dreams, to trade to the extent of permissible risk. In such situations, the goal of their companies is not to kill that wild ambition by introducing a voice into traders' heads saying: "I don't feel right about this."
It is more efficient to "subcontract" this kind of self-examination. Enforcement becomes a substitute for morality. Once that happens, conscience becomes unnecessary. In fact, it becomes an encumbrance. The problem is not the rise of the super-empowered individual. It is that the super-empowered individual tends more and more to be an amoral individual.
The writer is a senior editor at The Weekly Standard