Ambition, writes Lucy Kellaway, is both necessary and corrosive. She omits an important aspect here, which adds to its corrosiveness - class.

Class influences the level of ambition through two channels. One is that it distorts your awareness of opportunity. In Michael Apted's superb TV series Up, the privately-educated Andrew
knew (16'21" in) at the age of seven that he would go to Cambridge and become a lawyer. For the rest of us, our path to even modest success is not so pre-determined. I never thought about Oxford University until a teacher told me I could get in, and I never met anyone with a degree who wasn't a teacher until I was in my 20s. If you're not aware of the possibilities, you are less likely to be ambitious.

Another mechanism is that class sets the reference level of our income. When I realized that I would not have to worry about the leccy bill or becoming homeless, my ambition drained away. I was once one of those men brilliantly described by Adam Smith - a "poor man's son, whom heaven in its anger has visited with ambition". But I was lucky enough to have learned before my deathbed that "wealth and greatness are mere trinkets of frivolous utility." If you've nobody you want to impress, money soon loses its point.

By contrast, those from posher backgrounds can feel failures if they don't emulate their father's success. For many of them, wealth and greatness are not of frivolous utility but are instead the benchmarks by which they compare themselves to their parents and contemporaries.

Both these mechanisms help explain the fact that people who have experienced poverty as children earn less as adults even controlling for education.

But they also tell us something else. What seems to be ambition is in fact fear - whether it be the fear of poverty or the fear of falling short of parental expectations.

In this context, Lucy's advice that we must sometimes slough off ambition is a counsel of perfection. It's fine for those of us who have paid off the mortgage and so no longer fear homelessness. Younger people facing high rents or mortgage payments cannot afford a lack of ambition, even if they are consumed by anger when it is thwarted.

Again, class matters. It limits your options.

Here, though, we must ask: ambitious for what? Alasdair MacIntyre distinguished between goods of excellence such as mastery of a craft and goods of effectiveness such as wealth and power. Sometimes, pursuit of one brings the other: achieving the good of excellence in football will bring with it wealth, fame and at least some influence: Marcus Rashford's campaign against child poverty would have been less successful if he'd played for Stockport County.

In other cases, however, the two conflict. I doubt that the country's most excellent journalists are the best-paid. Being an excellent academic won't necessarily bring you the big money that comes from being university vice-chancellor. Prime Ministers aren't always drawn from the most excellent MPs or ministers. And bosses aren't necessarily the people who were best at the jobs their underlings do.

One component of that slippery term "neoliberalism" is, I suspect, the valorization of wealth, power and hierarchy over goods of excellence such as professional standards and craft skills.

Ambition for the goods of effectiveness can, though, be corrosive not just for individuals but for the economy. The man who is hungry for power and income will seek advancement even where he is not equipped for the job. And because employers (and voters) don't always know (pdf) what they are doing they will sometimes hire that man. Hence the Dilbert principle, of which Gavin Williamson is perhaps only the most prominent of many examples.

Here, incentives matter. Where there are disproportionate rewards in terms of income, power and status for advancement, people will seek promotion even when they are unsuited for it. You might prefer to be a first-rate coder than a third rate boss, but if being that boss means a big pay rise you will go for it. And so talent will be misallocated. What we have here therefore is yet another way (of many) in which big inequalities are bad for the economy.

To see my point, imagine an egalitarian socialistic society in which inequalities of power and income are small; there is less social distance between rich and poor families; and whose culture celebrates the goods of excellence in professional and craft work more than those of effectiveness: it would be a MacIntyrean or Walzerian-type utopia.

In this society, there'd be less incentive to be Dilberts like Gavin Williamson because you could earn a decent living as a first-rate coder (or third-rate fireplace salesman) and so have less need to "get on". What John Stuart Mill called "the trampling, crushing, elbowing, and treading on each other's heels" would diminish. And those who did "get on" would find their new roles, and the people they surround themselves with, less alien. So their ambition would not be the curse Smith thought it was. In these ways ambition would be less damaging to individuals and society.

You might think it hard to imagine such an environment. But then, as someone said, it is easier to imagine the end of the world than the end of capitalism.