A woman should say: 'Have I made him happy? Is he satisfied? Does he love me more than he loved me before? Is he likely to go to bed with another woman?' If he does, then it's the wife's fault because she is not trying to make him happy.
Finally there are simple ideas of which no definition can be given; there are also axioms or postulates, or in a word primary principles, which cannot be proved and have no need of proof.

