Dear Polly,

A "lack of appreciation", it seems to me, is our greatest, but least recognised, human failing, and a principal, underlying cause of most, if not all, our social, economic and environmental  ills.

Our growth-dependent economy depends on us not appreciating what we have, at least, not for long. If we did, it would stagnate or even go into recession.

Instead of appreciating the marvels of modern western civilisation (drinking water (often hot and cold) on tap in every house; electricity; central heating; toilet; bathroom; washing machine; etc. etc.) we simply take them all for granted; and left-wing, liberal intellectuals, like yourself - bless you - encourage people to believe that they have some kind of inherent "right" to them. Millions of immigrants have come here to take advantage - and who can blame them?

And it is not just material things that we take for granted (once we have them) and fail to appreciate (until we lose them), but knowledge too. Any pre-twentieth Century philosopher would give his right arm to know many of the things that are common knowledge to us, and which we often ram down our children's throats until it makes them sick. No wonder they do not appreciate it! If I had the finest foods rammed down my throat that would make me sick as well, and seriously impede my ability to appreciate it.

We are dependent on a growth-dependent economy which in turn is dependent on our addiction to the materialistic lifestyles and aspirations it engenders. It is what is known as a double bind, I believe, one which is forcing us to place an ever greater drain and strain on our planet's limited resources and finite carrying capacity.

Why are these things so difficult to recognise? Because it is all so familiar and "normal", which we are programmed and conditioned to accept as . . . . normal! (i.e. okay). I call them the "insanities of normality".

I share many of your social concerns and agree with much of what you write in you column, but everything pales into insignificance compared with our failure to recognise and face up to the threat posed by our non-sustainable, growth-dependent economy and materialistic lifestyles, which, given a global population that is approaching 7-9 billion, our planet, Spaceship Earth, cannot possibly support.

The consequences do not bear thinking about - which is perhaps another reason why we are so reluctant to do so.