One thing I've learnt in life is that nothing is true. So many of the assumptions that one has about life, art and politics turn out not to be true after all, once you subject them to much analysis. I then end up talking about these things with friends who, when I question an assumption, always say "But I thought...". A classic example of this is plastic bags. I used to think (or, rather, not think - that's the point) that plastic bags were definitely bad news and so we should presumably have a tax on them like Ireland's. Then I was exposed to the other side of the argument and I realised that it is much more complicated than that. In light of the latest news about this, I urge you to consider the facts, and make your own minds up. A tax might or might not be merited, but this certainly isn't a simple argument. I should, by the way, declare an interest, as I am a former employee of the British Retail Consortium.