ABSTRACT

Galileo had three children, Marie Curie had two. Between them they had an average of two and a half. We all know what children are, and we all know that each and every one of them is a whole child-nothing in reality corresponds to ‘two and a half children’. Average families aren’t theoretical entities, like electrons. We believe in electrons because we can make all sorts of wonderful predictions using them. We can do that with the average family, too-by knowing the size of the average family we can successfully predict how many day-care spaces will be needed next year, how many toys will be purchased at Christmas and how many visits will be made in July by the tooth fairy. Yet, in spite of the tremendous predictive power of ‘the average family’, no one is in the least tempted to say it corresponds to reality. Anti-realists think ‘electron’ fails to correspond to reality, too; but here at least we have a fight between plausible realist and antirealist views-no one champions the average family. What’s the difference?