The Cosmic River is a religion and philosophy followed by the river giants of Matarsah. To its followers, the Cosmic River is believed to be a primordial waterway that carries the world along in its current. In the cosmology of its faithful, it is a cyclical entity - though sometimes worshiped as a deity, it is rarely personified as such. The fresh waters that feed rivers on the Material Plane are thought to originate from the Cosmic River, seeping through the earth until they flow freely once more, eventually making their way out to the oceans and then to the primordial river to begin the cycle anew. The river giants of Matarsah also believe that the passing Lifewaters collect their memories, taking them to the Cosmic River to proceed through to the Material Plane again when their recollections and knowledge would be useful to future generations.
To some, the Cosmic River is a religion, while to others it is more of a secular philosophy. The difference to the giants is almost purely academic, and aside from this differing opinion as to the divinity of the River their beliefs are almost identical.
Some non-giant scholars associate the Cosmic River with Taliash, but the giants themselves rarely do so.