Advances in civilisation is a consequence of ever denser population. Were it not for the high cost of food, were fertilisers invented? Was it not because there are many mouths to feed, we learnt to farm rather than hunt? Is it not because we live so far apart, we must ride cars or trains rather than walk? If we all lived next to each other, would we have built telephones?<p>Thus it can be said civilisation is a necessary evil - if it were not necessary, we would not have done it - there is so much more leisure time in a hunter gatherer’s week than in a typical city resident’s. But in most places of the world it is no longer possible to live as a hunter gatherer. There are too many mouths to feed!