Man's inclination to justice makes democracy possible; but man's capacity for injustice makes it necessary.' The optimism we need to prevent ourselves from destroying our own democratic freedoms and, indeed, our own human habitat must be based on reasoned pessimism.
Monarchy is like a splendid ship, with all sails set it moves majestically on, but then it hits a rock and sinks for ever. Democracy is like a raft. It never sinks but, damn it, your feet are always in the water. That is a good metaphor, for raft, he implies, is simply swept along by the tide or the current; one can with a paddle or a plank steer a little to stay afloat, trim forward direction slightly to left or right, perhaps even slow down or speed up a little, but there is no turning back against the current of democracy.
Revolutions as often take place because the old regime simply collapse out of economic inefficiency and bureaucratic rigidity rather than for the reasons given out by their successors taking too much credit, however heroic their actions at the time of crisis (but so often in the past hopeless).