---
title: "Vasubandhu’s dream · Simulation Hypothesis"
url: https://simulation-hypothesis.com/thinkers/vasubandhu
description: "A shared, orderly world that affects us can appear without outside objects. Vasubandhu argues it with a dream, hungry ghosts and a nightmare of hell."
license: https://creativecommons.org/licenses/by/4.0/
credit: "Ross Allan Dahl, Simulation Hypothesis (simulation-hypothesis.com)"
---

[Thinkers](https://simulation-hypothesis.com/thinkers)3/14

# Vasubandhu’s dream

Vasubandhu, Viṃśatikā (Twenty Verses on Appearance Only) · 4th–5th century AD

A shared, orderly world that affects us can appear without outside objects. Vasubandhu argues it with a dream, hungry ghosts and a nightmare of hell.

Vasubandhu, an Indian Buddhist philosopher of the Yogācāra school, opens the Twenty Verses with a thesis. Everything in the three realms is representation only (vijñaptimātra), because objects can appear that aren’t there. A person with an eye disease sees hairs and a second moon. The Stanford Encyclopedia dates him to the fourth to fifth century AD, and ties him to the reign of Chandragupta II (380–415) through Paramārtha’s biography. His aim is liberation from suffering. The question he asks is whether the world needs outside objects to look the way it does.

He states the strongest objection himself. A dream is a poor model, says the opponent, because waking life differs in four ways. What you see is tied to a place. It’s tied to a time. Many beings share it. And it has effects. A dreamer’s lover can’t be touched, and a dreamed meal doesn’t feed anyone. Those four features are what make a world look independent of the mind. They’re also what a simulation would have to supply to be convincing.

He answers them one at a time. In dreams, too, certain things show up at certain places and times, so a regular order doesn’t need a physical object. For sharing, he points to the hungry ghosts (pretas). They all see a river as pus, because their past actions ripen in similar ways. He also points to the guardians of hell, whom all its inhabitants see. A shared appearance has a shared cause in the minds that have it, not in an object. For effects, he points to the nocturnal emission, a bodily effect from a dream encounter with no partner.

He also takes up other minds. Minds, he says, influence one another. So other beings are no less real for lacking outside bodies in the sense the objector means. And what you know of another’s mind isn’t knowledge of it as it really is (verses 18–21 on his numbering, and translations differ). He adds that until awakening, you don’t see that what appears isn’t as it seems (verse 17). That’s close to Zhuangzi’s great awakening.

For the sandbox, this is the cleanest ancient statement that observers agreeing doesn’t prove there’s a world outside the representation. One computed state, sent to many players, would produce exactly the shared, ordered, effective appearances he lists. The difference from Berkeley is that Vasubandhu needs no divine perceiver. The consistency comes from the causal history of the streams of minds.

In the sandbox · LobbyMultiplayer is Vasubandhu’s third objection: how can many beings share one world if there’s no outside object? In the Lobby control, multiplayer and players-plus-NPCs both send one consistent state to many minds. At single player, the same appearances are produced for one. On his view, the setting changes the computing needed but not what anyone sees.

[Open the sandbox ▸](https://simulation-hypothesis.com/sandbox)

In the trees

[Dreams · Simulations](https://simulation-hypothesis.com/trees/simulations?n=w-dreams)

## Sources

[Vasubandhu](https://plato.stanford.edu/entries/vasubandhu/)

Stanford Encyclopedia of Philosophy, sec. on the Twenty Verses (the dream, the four objections and replies)

[Yogācāra](https://plato.stanford.edu/entries/yogacara/)

Stanford Encyclopedia of Philosophy

Viṃśatikā-kārikā with Vṛtti (Twenty Verses)

Vasubandhu, 4th–5th c. AD. Translations: Kapstein, in Reason’s Traces (Wisdom, 2001); Anacker, Seven Works of Vasubandhu (Motilal, 1984); Tola and Dragonetti (2004). Verse numbers vary between translations.

In the Library

[Ontology](https://simulation-hypothesis.com/library/ontology)[The problem of other minds](https://simulation-hypothesis.com/library/other-minds)[Epistemology](https://simulation-hypothesis.com/library/epistemology)[Skepticism](https://simulation-hypothesis.com/library/skepticism)

[◂ Zhuangzi’s butterfly](https://simulation-hypothesis.com/thinkers/zhuangzi)[Shankara’s māyā ▸](https://simulation-hypothesis.com/thinkers/shankara)