Twenty four Tirthankars are born in every Utsarpini phase and the Avasarpini phase. They, by means of their endeavor, become absolutely enlightened; they become devoid of attachments; they become Jinas; and for the spiritual welfare of all creatures in the Universe, they establish and expound the philosophy. Because they establish the philosophy, they are called Tirthankars. One definition of tirth is Sangha or society, Chauvanno Sangho tittham. This four-fold society of Sadhus, Sadhvis, Shravaks and Shravikas is together called tirtha.