The Eurofighter and you.

What's not to like? Well, it's a grossly over-expensive death-dealer from the sky. Endorsed by the European Union! So unless you are a Continental arms manufacture I expect there is something in there to get your bile flowing.

The Eurofighter is also at the forefront of aircraft design. In that regard, I suggest that you, it and I share a certain kinship.

Airplanes can be seen as having two parts: an 'airframe' and some kind of engine to push it along. Independence between those functions means if you have engine failure, even on an Airbus A320, the right pilot can land it on the Hudson River.

That landing was possible because the gracefulness of the machine lent it some predictability. Predictability is not an asset when being chased in a dogfight. In that context, it is useful for the plane to 'want' to turn harder or faster than your pursuer anticipates.

So the Eurofighter is one of a small range of modern aircraft that is designed to be relatively unstable in the air. The computer interface between the pilot and the aircraft's flight ensures that it goes where intended. If its computers malfunctioned, it would fly like a brick.

This is a relatively new concept in aircraft design, but it is aeons old in the history of natural selection. Compare the silhouettes an albatross and a swift. If you have to continually engage in 'dogfights' with insects to earn your crust, a compact shape is more likely to make you Top Gun. (You might be fast enough, into the bargain, to be called a 'swift'. But that being the case, why call something just as successful a 'swallow'?)

Therefore, in the right context, instability is a Good Thing.

As upright bipeds, we are definitively unstable when we stand. Even while sober.

That is not a curse. It's a blessing. Instability allows us a kind of physical freedom that our more sure-footed cousins have to live without

That kind of freedom is called 'poise' (to refer to is as 'good posture' misses its inherent dynamism).

Like the Eurofighter, our computer programming does not do something as straightforward as 'keep us upright'. Instead we are always in the process of just-about-falling-over. But our software makes the continual minimal corrections that prevent the threat of crash-landing. Until we want to start falling over, like when we effortlessly start to walk.

As always, the same vocabulary applies to our minds as to our bodies. "Mentally unstable" and "emotionally unstable" have strong negative connotations, but what is less human than someone unsusceptible to change?

The stability of a depressed person's emotionality is hardly a subject of envy. Their increased mental stability is also reflected in their physical stability; they are closer to the ground. Rather than being able to "keep their chin up" they are, in every way, 'depressed'.

Mental poise is a sign of good humane functioning. It is a person's ability to allow their emotions and ideas to change as their circumstances change. Not to be at the mercy of every capricious moment, but to be a living, responsive part of their own world. Like standing, it is a balancing act.

The aeronautical engineers have a technical term for the deliberate tendency of an aircraft to change direction of its own accord. Delightfully, they call it 'relaxed stability' (as opposed to 'positive stability'). Who wouldn't wish that for themselves?

I have an ambition now to give Alexander Technique lessons to an aircraft designer. When I ask her how she feels afterwards, I'd like her to say "I feel like I have relaxed stability". She might not be able to take flight as a result, but at least she will be better able to dance.