Modern economies do not differentiate between renewable and non-renewable materials, as its method is to measures everything by means of a money price. Thus, taking various alternatives fuels, like coal, oil, wood or water power: the only difference between them recognised by modern economics is relative cost per equivalent unit. The cheapest is automatically the one to be preferred, as to do otherwise would be irrational and 'uneconomic'. From a Buddhist point of view of course this will not do, the essential difference between non-renewable fuels like coal and oil on the one hand and renewable fuels like wood and water power on the other cannot be simply overlooked. Non-renewable goods must be used only if they are indispensable, and then only with the greatest care and the highest concern for conservation. To use them carelessly or extravagantly is an act of violence, and while complete non-violence may not be possible on earth, it is nonetheless the duty of man to aim at deal of non-violence in all he does.