Then again, that is most useful which is no way detrimental. Now fire easily becomes most pernicious, but the nature of water is never prejudicial. In the next place, that is most useful which affords the benefit which it brings with least expense, and without any preparation. But the benefit of fire requires cost and materials, and therefore the rich make more use of it than the poor, and princes than private persons; but water has that kindness for mankind, that it freely offers itself to all alike, a benefit perfect in itself, indigent of nothing, and wanting neither tools nor implements.