It is said that we need the best as a measure against which to test the second-best, to show us how far we are deviating from the best. In this sense, the best is the ideal to which the second-best aspires. But if the ideal is impractical because inconsonant with human nature, how or why should we aspire to it? The case for the second-best goes beyond practicality. More serious is the fact that the attempt to realise the unrealisable is likely to be pernicious.

Voltaire is credited with the dictum: "The best is the enemy of the good." What he did write was "Le mieux est l'ennemi du bien" - "le mieux" translatable as either the better or the best. It is interesting that the French use the same word for concepts that in English are so sharply distinguished: the better and the best. One might almost make this symbolic of the historic differences between the two countries. The unambiguous English version of that dictum makes it clear that it is only the best that is the enemy of the good, and that the better, the second-best, is the friend and ally of the good.

Indeed, the best may be more pernicious still, for it is not only the enemy of the good; it may be an invitation to the worst. The perils of utopianism are by now all too familiar. It was in the name of the best - of so-called "ideals" - that some of the worst tyrannies have been perpetrated and rationalised. Robespierre's Reign of Terror was instituted in the name of the "Republic of Virtue", which was a conscious adaptation of Rousseau's "reign of virtue".