Where medicine meets the boundaries of manhood and womanhood.

W e are defined by sexual dimorphism. Male and female, the sexes we are (and are perceived to be), affect how we feel, how we behave and how we interact with others. We look around and see all complex creatures, including ourselves, as either male or female. This is so much a part of our daily existence that it reinforces the idea of manhood and womanhood as expressions of a natural order. We regard this division into two sexes as one of the great eternal verities and tend to experience the difference between the sexes as rather absolute. Subjectively, man and woman are seen as opposites, poles apart and mutually exclusive forms of human existence. In daily medical practice, this duality of the sexes also tends to be regarded as axiomatic. The biological determinants of male and female somatic sexual differentiation have been elucidated and these insights have contributed substantially to the definition and diagnosis of errors of sexual differentiation. As a result, when such errors are encountered, treatments can often be provided to enable subjects to lead more conformable lives as men and women. In some exceptional cases, however, normal medical practice is unable to offer solace to subjects whose manhood or womanhood is troubled. This contribution looks at some of these unusual conditions. It addresses the sex assignment of newborns afflicted with sexual differentiation errors as well as the phenomenon of transsexualism. Both conditions have their biological aspects, but both also have ramifications into the psychosexual and psychosocial aspects of manhood and womanhood. Both demonstrate that in the practice of medicine, the concepts of manhood and womanhood may extend beyond the confines of traditional biomedical thinking.