In all human affairs, conflicting influences are required to keep one another alive and efficient even for their own proper uses
 John Stuart Mill, Considerations on Representative Government (1861). copy citation

Context

“the patient obstructiveness of the body being in the long run more than a match for the fitful energy of one man. The Chinese government, a bureaucracy of Mandarins, is, as far as known to us, another apparent example of the same qualities and defects. In all human affairs, conflicting influences are required to keep one another alive and efficient even for their own proper uses; and the exclusive pursuit of one good object, apart from some other which should accompany it, ends not in excess of one and defect of the other, but in the decay and loss even of that which has been exclusively cared for.” source