 At a given time in the past, it may well be that false theories vastly outnumber true theories. In that case, even if only a small proportion of false theories are successful, and even if a large proportion of true theories are successful, the successful false theories may outnumber the successful true theories. So the fact that successful false theories outnumber successful true theories at some time does nothing to undermine the reliability of success as a test for truth at that time, let alone at other times (2001: 376–7).