From the fact that it is practised by the aboriginal Australians, it must either have originated tens of thousands of years ago, before they were isolated from other peoples, or be the spontaneous response to similar conditions in widely separate places.
When nomads settled and became farmers, they found religious reasons for continuing what had become a useless custom. It is easy to see how the operation came to be invested with meaning, given its emotionally charged object. The Jewish variety was for many centuries just the symbolic cutting of the tip; removal of the whole foreskin was introduced only when too many Jews started passing themselves off as uncircumcised in the Greek world.
Female "circumcision" presumably originated by analogy with the male variety, since it does not occur without it. Al-Shafi'i, the only doctor of Islamic law who taught that it was obligatory to circumcise girls, explicitly based his doctrine on this analogy.
P J STEWART
St Anne's College, Oxford