It is true that this proviso is hardly necessary as regards the multiplication table, but knowledge in practical affairs has not the certainty or the precision of arithmetic. Suppose I say "democracy is a good thing": I must admit, first, that I am less sure of this than I am that two and two are four, and secondly, that "democracy" is a somewhat vague term which I cannot define precisely. We ought to say, therefore: "I am fairly certain that it is a good thing if a government has something of the characteristics that are common to the British and American Constitutions," or something of this sort. And one of the aims of education ought to be to make such a statement more effective from a platform than the usual type of political slogan.
1940s, Philosophy for Laymen (1946)
