Jainism, traditionally known as Jain Dharma, is an ancient Indian religion and the method of acquiring perfect knowledge of self and universe and perfect joy through extrasensory means as sensory means are inadequate to acquire them. The method is summarized in its religious text Pravachanasara first published in english by Cambridge University Press in 1934. It is further elaborated in Samayasāra and Tattvartha Sutra from parallelist and interactive lenses respectively. Jain dharma traces its spiritual ideas and history through a succession of twenty-four leaders or Tirthankaras, with the first in current time cycle being Rishabhanatha, whom the tradition holds to have lived millions of years ago, the twenty-third tirthankara Parshvanatha whom historians date to 8th century BCE, and the 24th tirthankara, Mahavira around 600 BCE. Jainism is considered to be an eternal dharma with the tirthankaras guiding every time cycle of the cosmology.