As Indian civilisation further developed and the writing of the Upanishads around 500 BCE, it was somewhere between the 1st and 6th centuries that the Kama Sutra, originally known as Vatsyayana Kamasutram ('Vatsyayana's Aphorisms on Love'), was written. This philosophical work on kama shastra, or 'science of love', was intended as both an exploration of human desire, including infidelity, and a technical guide to pleasing a sexual partner within a marriage. This is not the only example of such a work in ancient India, but is the most widely known in modern times. It is probably during this period that the text spread to ancient China, along with Buddhist scriptures, where Chinese versions were written.