According to Indologists Constance Jones and James D. Ryan, the yoni symbolizes the female principle in all life forms as well as the "earth's seasonal and vegetative cycles", thus is an emblem of cosmological significance. The yoni is a metaphor for nature's gateway of all births, particularly in the Shaktism and Shaivism traditions of Hinduism, as well as the esoteric Kaula and Tantra sects. "Yoni" together with the "lingam" is a symbol for "prakriti", its cyclic creation and dissolution. According to Corinne Dempsey – a professor of Religious Studies, yoni is an "aniconic form of the goddess" in Hinduism, the feminine principle "Shakti".