Quotation on linear minds in a non-linear world

Linear relationships are easy to think about..... Nonlinear systems generally cannot be solved and cannot be added together... Nonlinearity means that the act of playing the game has a way of changing the rules... That twisted change-ability makes nonlinearity hard to calculate, but it also creates rich kinds of behaviour that never occur in linear systems. - James Gleick, Chaos: Making a New Science (taken from 'Thinking in Systems' by Donella H Meadows)