More recent applications include Robert Watson-Watt propounding a "cult of the imperfect", which he stated as "Give them the third best to go on with; the second best comes too late, the best never comes."[3] Economist George Stigler's assertion that "If you never miss a plane, you're spending too much time at the airport."[4][5] And, in the field of computer program optimization, Donald Knuth's statement that "Premature optimization is the root of all evil".[6]