In Buddhism, conceptual proliferation (or mental proliferation) (Pali: papañca, Template:Lang-skt, Chinese: 戲論) refers to conceptualization of the world through the use of ever-expanding language and concepts. The translation of papañca as conceptual proliferation was first made by Katukurunde Nanananda Thera in his research monograph Concept and Reality. It is a useful concept, not only in Buddhism but in many other fields (see below).
It is intended to elucidate reality, although it has the unexpected result of blotting out or reducing direct nonverbal sensory perception. In part, this is due to each person's limitation of how many things they can pay attention to at the same time. A person who can only attend to two things at once, may be able to receive a direct sensory picture of the tree while at the same time saying "The apple tree in the garden," but the picture will not be as complete.
The term is mentioned in a variety of suttas in the Pali canon, such as the Madhupindika Sutta (MN 18), and is mentioned in Mahayana Buddhism as well. When referencing the concepts derived from this process, such concepts are referred to in Pali as papañca-saññā-sankhā.