Hindu

Hindu
In the Mandukya Upanishad, part of the Veda scriptures of Indian Hinduism, a dream is one of three states that the soul experiences during its lifetime, the other two states being the waking state and the sleep state.[31]

Buddhist
In Buddhism, ideas about dreams are similar to the classical and folk traditions in South Asia. The same dream is sometimes experienced by multiple people, as in the case of the Buddha-to-be, before he is leaving his home. It is described in the Mahāvastu that several of the Buddha’s relatives had premonitory dreams preceding this. Some dreams are also seen to transcend time: the Buddha-to-be has certain dreams that are the same as those of previous Buddhas, the Lalitavistara states. In Buddhist literature, dreams often function as a “signpost” motif to mark certain stages in the life of the main character.[32]

Buddhist views about dreams are expressed in the Pāli Commentaries and the Milinda Pañhā.[32]

Philosophical realism
Main article: Dream argument

A Dream of a Girl Before a Sunrise by Karl Bryullov (1830–1833)
Some philosophers have concluded that what we think of as the “real world” could be or is an illusion (an idea known as the skeptical hypothesis about ontology).

The first recorded mention of the idea was by Zhuangzi, and it is also discussed in Hinduism, which makes extensive use of the argument in its writings.[33] It was formally introduced to Western philosophy by Descartes in the 17th century in his Meditations on First Philosophy. Stimulus, usually an auditory one, becomes a part of a dream, eventually then awakening the dreamer.

Postclassical and medieval history
Some Indigenous American tribes and Mexican civilizations believe that dreams are a way of visiting and having contact with their ancestors.[34] Some Native American tribes used vision quests as a rite of passage, fasting and praying until an anticipated guiding dream was received, to be shared with the rest of the tribe upon their return.[35][36]