According to ancient Indian belief, the Supreme Being is one complete sex, possessing within itself both the male and female principles. Such a deity is said to be Ardhanarishvara, a Sanskrit term meaning "Lord Whose Half is female," embodying the qualities of both genders.
Shiva is often represented as Ardhanarishvara, where his form is fused halfway into the body of his spouse Parvati. This is exemplified in the present sculpture where the bisexual image is divided vertically, the right-hand half, which is male, being that of Shiva proper, and the left side having female anatomy, that of Parvati.
Corresponding to the ideal of Shiva, the right half is clad in a tiger-skin loin cloth, and Parvati on the left is draped in a sari. She also has a breast, covered in a bodice as also an elaborate nose-ring. The jewelry of the two halves including necklaces, bracelets, and armlets, are different from each other. At Shiva's side can be seen his mount, Nandi the bull, and near Parvati is her lion.
An original understanding of the Ardhanarishvara concept was expressed by Kalidasa, the Sanskrit poet believed to have lived in the 5th century AD. At the head of his poem 'Raghuvamsha,' he addressed a verse to Shiva and Parvati, comparing the literary fusion of meaning (artha, masculine) and the speech which utters it (vach, feminine) to their harmonious union in which, although as inextricably conjoined as a word is with its sense, the couple yet retained their individual importance.
In the mundane world all men and women reflect the duality expressed in the concept of Ardhanarishvara. Every man and woman contains within himself or herself both male and female principles. A man is a man only because of the excess in him of the principle of masculinity, and a woman is a woman because of the predominance of the principle of femininity. It is believed that this maleness and femaleness generally remain in conflict within the individual and can to some extent be made to harmonize with the opposite sex during sexual intercourse when the couple, symbolizing Shiva and Parvati, realize the Absolute.
Indeed, while emphasizing the essential non duality of the supreme principle, this image is remarkable for the precision with which it distinguishes the male and female elements of the deity while harmoniously fusing them into a single form.