The dream argument is the postulation that the act of dreaming provides preliminary evidence that the

sense A sense is a biological system used by an organism for sensation, the process of gathering information about the surroundings through the detection of Stimulus (physiology), stimuli. Although, in some cultures, five human senses were traditio ...

s we trust to distinguish

reality Reality is the sum or aggregate of everything in existence; everything that is not imagination, imaginary. Different Culture, cultures and Academic discipline, academic disciplines conceptualize it in various ways. Philosophical questions abo ...

from

illusion An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people. Illusions may ...

should not be fully trusted, and therefore, any state that is dependent on our senses should at the very least be carefully examined and rigorously tested to determine whether it is in fact reality.

Synopsis

While

dream A dream is a succession of images, ideas, emotions, and sensation (psychology), sensations that usually occur involuntarily in the mind during certain stages of sleep. Humans spend about two hours dreaming per night, and each dream lasts around ...

ing, one does not normally realize one is dreaming. On more rare occasions, the dream may be contained inside another dream with the very act of realizing that one is dreaming, itself, being only a dream that one is not aware of having. This has led

philosophers Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, value, mind, and language. It is a rational and critical inquiry that reflects on ...

to wonder whether it is possible for one ever to be certain, at any given point in time, that one is not in fact dreaming, or whether indeed it could be possible for one to remain in a perpetual dream state and never experience the reality of

wakefulness Wakefulness is a daily recurring brain state and state of consciousness in which an individual is conscious and engages in coherent cognition, cognitive and behavioral responses to the external world. Being awake is the opposite of being asleep, ...

at all. In

Western philosophy Western philosophy refers to the Philosophy, philosophical thought, traditions and works of the Western world. Historically, the term refers to the philosophical thinking of Western culture, beginning with the ancient Greek philosophy of the Pre ...

this philosophical puzzle was referred to by

Plato Plato ( ; Greek language, Greek: , ; born BC, died 348/347 BC) was an ancient Greek philosopher of the Classical Greece, Classical period who is considered a foundational thinker in Western philosophy and an innovator of the writte ...

( ''Theaetetus'' 158b-d),

Aristotle Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...

( ''Metaphysics'' 1011a6), and the Academic Skeptics. It is now best known from

René Descartes René Descartes ( , ; ; 31 March 1596 – 11 February 1650) was a French philosopher, scientist, and mathematician, widely considered a seminal figure in the emergence of modern philosophy and Modern science, science. Mathematics was paramou ...

' '' Meditations on First Philosophy''. The dream

argument An argument is a series of sentences, statements, or propositions some of which are called premises and one is the conclusion. The purpose of an argument is to give reasons for one's conclusion via justification, explanation, and/or persu ...

has become one of the most prominent skeptical hypotheses. In

Eastern philosophy Eastern philosophy (also called Asian philosophy or Oriental philosophy) includes the various philosophies that originated in East and South Asia, including Chinese philosophy, Japanese philosophy, Korean philosophy, and Vietnamese philoso ...

this type of argument is sometimes referred to as the " Zhuangzi paradox":

He who dreams of drinking wine may weep when morning comes; he who dreams of weeping may in the morning go off to hunt. While he is dreaming he does not know it is a dream, and in his dream he may even try to interpret a dream. Only after he wakes does he know it was a dream. And someday there will be a great awakening when we know that this is all a great dream. Yet the stupid believe they are awake, busily and brightly assuming they understand things, calling this man ruler, that one herdsman—how dense! Confucius and you are both dreaming! And when I say you are dreaming, I am dreaming, too. Words like these will be labeled the Supreme Swindle. Yet, after ten thousand generations, a great sage may appear who will know their meaning, and it will still be as though he appeared with astonishing speed.

The

Yogachara Yogachara (, IAST: ') is an influential tradition of Buddhist philosophy and psychology emphasizing the study of cognition, perception, and consciousness through the interior lens of meditation, as well as philosophical reasoning (hetuvidyā). ...

philosopher

Vasubandhu Vasubandhu (; Tibetan: དབྱིག་གཉེན་ ; floruit, fl. 4th to 5th century CE) was an influential Indian bhikkhu, Buddhist monk and scholar. He was a philosopher who wrote commentary on the Abhidharma, from the perspectives of th ...

(4th to 5th century C.E.) referenced the argument in his "Twenty verses on appearance only." The dream argument came to feature prominently in

Mahayana Mahāyāna ( ; , , ; ) is a term for a broad group of Buddhist traditions, Buddhist texts#Mahāyāna texts, texts, Buddhist philosophy, philosophies, and practices developed in ancient India ( onwards). It is considered one of the three main ex ...

and

Tibetan Buddhist Tibetan Buddhism is a form of Buddhism practiced in Tibet, Bhutan and Mongolia. It also has a sizable number of adherents in the areas surrounding the Himalayas, including the Indian regions of Ladakh, Darjeeling, Sikkim, and Arunachal Prades ...

philosophy. Some schools of thought (''e.g.'',

Dzogchen Dzogchen ( 'Great Completion' or 'Great Perfection'), also known as ''atiyoga'' ( utmost yoga), is a tradition of teachings in Indo-Tibetan Buddhism and Bön aimed at discovering and continuing in the ultimate ground of existence. The goal ...

) consider ''perceived

'' to be literally unreal. As Chögyal Namkhai Norbu puts it: "In a real sense, all the visions that we see in our lifetime are like a big dream ..." Chögyal Namkhai Norbu ''Dream Yoga And The Practice Of Natural Light'' Edited and introduced by Michael Katz, Snow Lion Publications, Ithaca, NY, , pp. 42, 46, 48, 96, 105. In this context, the term 'visions' denotes not only

visual perception Visual perception is the ability to detect light and use it to form an image of the surrounding Biophysical environment, environment. Photodetection without image formation is classified as ''light sensing''. In most vertebrates, visual percept ...

s, but also appearances perceived through all

s, including sounds, smells,

taste The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste. Taste is the perception stimulated when a substance in the mouth biochemistry, reacts chemically with taste receptor cells l ...

s, and tactile sensations, and operations on perceived mental objects.

Simulated reality

Dreaming provides a springboard for those who question whether our own reality may be an illusion. The ability of the mind to be tricked into believing a mentally generated world is the "real world" means at least one variety of simulated reality is a common, even nightly event. Those who argue that the world is not simulated must concede that the mind—at least the sleeping mind—is not itself an entirely reliable mechanism for attempting to differentiate reality from illusion.

Critical discussion

In the past, philosophers

John Locke John Locke (; 29 August 1632 (Old Style and New Style dates, O.S.) – 28 October 1704 (Old Style and New Style dates, O.S.)) was an English philosopher and physician, widely regarded as one of the most influential of the Enlightenment thi ...

and

Thomas Hobbes Thomas Hobbes ( ; 5 April 1588 – 4 December 1679) was an English philosopher, best known for his 1651 book ''Leviathan (Hobbes book), Leviathan'', in which he expounds an influential formulation of social contract theory. He is considered t ...

have separately attempted to refute Descartes's account of the dream argument. Locke claimed that you cannot experience pain in dreams. Various scientific studies conducted within the last few decades provided evidence against Locke's claim by concluding that pain in dreams can occur, but on very rare occasions. Philosopher Ben Springett has said that Locke might respond to this by stating that the agonizing pain of stepping into a fire is non-comparable to stepping into a fire in a dream. Hobbes claimed that dreams are susceptible to absurdity while the waking life is not. Many contemporary philosophers have attempted to refute dream skepticism in detail (see, e.g., Stone (1984)).

Ernest Sosa Ernest Sosa (; ; born June 17, 1940) is an American philosopher primarily interested in epistemology. Since 2007 he has been Board of Governors Professor of Philosophy at Rutgers University, but he spent most of his career at Brown University. ...

(2007) devoted a chapter of a monograph to the topic, in which he presented a new theory of dreaming and argued that his theory raises a new argument for skepticism, which he attempted to refute. In ''A Virtue Epistemology: Apt Belief and Reflective Knowledge'', he states: "in dreaming we do not really believe; we only make-believe." Jonathan Ichikawa (2008) and Nathan Ballantyne & Ian Evans (2010) have offered critiques of Sosa's proposed solution. Ichikawa argued that as we cannot tell whether our beliefs in waking life are truly beliefs and not imaginings, like in a dream, we are still not able to tell whether we are awake or dreaming. The dream hypothesis is also used to develop other philosophical concepts, such as Valberg's personal horizon: what this world would be internal to if ''this'' were all a dream.

Dream skepticism

Norman Malcolm Norman Adrian Malcolm (; 11 June 1911 – 4 August 1990) was an American philosophy, philosopher. Malcolm was primarily active in the fields of epistemology, philosophy of mind, and philosophy of psychology. Biography Malcolm was born in Selden ...

in his monograph "Dreaming" (published in 1959) elaborated on Wittgenstein's question as to whether it really mattered if people who tell dreams "really had these images while they slept, or whether it merely seems so to them on waking". He argues that the sentence "I am asleep" is a senseless form of words; that dreams cannot exist independently of the waking impression; and that skepticism based on dreaming "comes from confusing the historical and dream telling senses... f..the past tense" (page 120). In the chapter: "Do I Know I Am Awake ?" he argues that we do not have to say: "I know that I am awake" simply because it would be absurd to deny that one is awake. Philosopher

Daniel Dennett Daniel Clement Dennett III (March 28, 1942 – April 19, 2024) was an American philosopher and cognitive scientist. His research centered on the philosophy of mind, the philosophy of science, and the philosophy of biology, particularly as those ...

expanded on this idea with his cassette tape hypothesis of dreaming. He conjectured that dreams are not real conscious experiences, and are instead pseudo-memories that emerge upon awakening from sleep. These pseudo-memories do not correspond to any real dream experiences, and are instead strictly fabrications of experiences that never occurred. Philosopher Jennifer Windt has counter-argued against dream skepticism, drawing on the psychology of lucid dreaming, and has advanced a conceptual framework of dreaming as real imaginative experiences.

Notes

References