One way of looking at Impossibility Theorem is that we proposed some criteria for what a good system should be: what is it you want from a voting system, and impose some conditions. And then ask: can you have a voting system that guarantees that?

Now virtue may not always be its own reward, but in any case it is not usually bought and paid for at market rates.

Vast ills have followed a belief in certainty.

I don't believe that unemployment is all voluntary, by anticipation of future wage movements or this sort of thing. I know you can modify the models by taking into account the indivisibilities, but I don't really think that people are voluntarily unemployed.

The MD is well aware that the forecasts are no good but he needs them for planning purposes.

Family is a difficult matter. I must admit I do not know that the state can intervene successfully in a family. It's a fact that everything is connected with the individualist temperament, the kind of economic environment which stresses the individual, but this is not directly the result of a state policy, nor do I see any good way by which the state could intervene except in some marginal ways.

Usefulness depends on tractability.