Exploring the Connection Between Mind and Dreams

Every night, the mind embarks on a journey it did not consciously choose – a journey full of vivid images, impossible scenarios, and half-remembered sensations that dissolve at waking. For most of human history, dreams were treated as divine messages or supernatural omens. Aristotle was among the first to ask a more grounded question: what does dreaming tell us about the nature of the mind itself? His answer, developed over two millennia ago, remains philosophically rich and surprisingly relevant today.

Aristotle’s place in the history of mind and dreams 🔗

Aristotle regarded psychology as a part of natural philosophy, and he wrote extensively on the philosophy of mind – not just in his major treatise De Anima (On the Soul), but also in a set of shorter biological investigations known as the Parva Naturalia, which includes dedicated works on sense-perception, memory, sleep, and dreams. These works contain the only systematic account of dreams and prophecy in sleep that has been transmitted to us from ancient Greek philosophy, making Aristotle a foundational figure in the study of the dreaming mind.

His three dedicated treatises on the subject – De Somno et Vigilia (On Sleep and Waking), De Insomniis (On Dreams), and De Divinatione per Somnum (On Divination Through Sleep) – together form a coherent, naturalistic theory of what happens to consciousness during sleep. His approach was empirical and biological, not mystical. Dreams, for Aristotle, were not sent by gods. They were products of the mind and body working together.

The non-dualistic view: soul and body as one 🔗

To understand Aristotle’s theory of dreams, you first need to understand how he conceived of the soul. This is where he parts ways sharply with his predecessors – especially Plato – and with later thinkers like René Descartes, who famously treated the mind and body as two entirely separate substances.

For Aristotle, the soul is not an independently existing substance. It is the form of the body – not a separate substance inside another substance of a different kind, but a capacity, the very thing that makes a living body alive. In his own words from De Anima, the soul is “the first actuality of a natural organic body.” This means the soul is what enables the body to perform the activities characteristic of its kind – nutrition, growth, perception, movement, and thought.

This is a fundamentally non-dualistic position. Aristotle thought that humans and other organisms are inextricably psycho-physical, and so are their capacities and activities – there is no problem of explaining the regular connection between a psychological state and a physical one, because they are simply one thing described from two angles. Anger, for example, is not a purely mental event that happens to cause a physical response. It is a single unified event that is both a desire for retaliation and a particular state of the blood – inseparably at once.

This integrated view of soul and body is the lens through which Aristotle approaches dreaming. If the mind and body are not separate, then what happens during sleep is not purely mental – it is a joint event involving both.

What happens to the mind during sleep? 🔗

Aristotle considers sleep to be a kind of privation of waking – not its opposite, but its temporary absence. Sleep and waking are paired states of the same living being. During sleep, the external senses are at rest. The eyes cannot see. The ears do not register sound as they would in the waking state. But this suspension of the senses does not mean the mind goes entirely quiet.

What continues to operate, crucially, is phantasia – the faculty of imagination. Aristotle describes imagination as the faculty by which a mental image (phantasma) is presented to us – a motion generated by actual perception, associated with sense-perception, memory, thinking, and dreams. In waking life, imagination works alongside the senses and is kept in check by them. But in sleep, the senses withdraw, and imagination is left to operate on its own.

When we are awake and perceive an object in the outside world, an affection or impression remains in the sense organ even after the object is no longer present. During sleep, these residual impressions – stored in the imagination – flow back toward the sense organs and produce the experience of dreaming. This is why dreams feel so real: they are not arbitrary inventions, but re-activations of actual sensory impressions from waking life, now replayed without the corrective presence of the senses themselves.

Dreams as products of imagination, not divine will 🔗

Aristotle saw imagination as the result of sensory and subjective perception occurring after the disappearance of the sensed object, recognising that the human mind forms powerful afterimages of things no longer present. He carried this insight into the realm of sleep and applied it to dreaming. The content of a dream, in this account, is built from the raw material of waking experience – filtered, transformed, and replayed by the imaginative faculty.

This is a significant departure from the prevailing Greek view of dreams as divine communications. Aristotle in his treatise De Divinatione per Somnum acknowledges that dreams sometimes appear to foretell the future, but rejects the popular belief in the divinatory power of dreams. He argues that since other animals also dream, they cannot be divine messages sent to humans. Any apparent prophetic quality in a dream is either coincidence or a result of the dreamer’s bodily state influencing the content – for instance, a person who is about to fall ill might dream of physical discomfort before conscious symptoms appear.

In De Insomniis, Aristotle concludes that dreaming is ultimately due to residual movements of the sensory organs during sleep. He even suggests that indigestion might cause dreams, since excessive physical activity generates disturbances that feed into the imagination. What seems mystical, in Aristotle’s view, has a perfectly natural explanation rooted in the biology of the sleeping body.

The distinction between waking and dreaming consciousness 🔗

One of Aristotle’s most philosophically important observations concerns how we relate to our own mental states differently when asleep versus awake. In the waking state, we easily distinguish between an external object and an imagined one. We know, for instance, that the image of a friend we are recalling is not the same as the friend standing before us. This discrimination is what Aristotle calls the function of the common sense – the faculty that coordinates and evaluates inputs from the individual senses.

In sleep, this common sense faculty – the ability to distinguish between what is real and external and what is imagined – is absent or greatly diminished. This is what produces the profound sense of reality we experience in dreams, and why we accept dream events as actual while they are happening. The imagination, unchecked by perception and rational judgment, presents its images with the same force as real sensory experience.

Aristotle also compares the experience of dreaming to hallucinations, noting that the faculty by which we are subject to illusion when affected by disease in the waking state is the same faculty that produces illusory effects in sleep. Dreaming is, in this sense, a kind of natural hallucination – not pathological, but structurally similar to those perceptual distortions that occur when the mind’s grip on external reality loosens.

Lucid dreaming: a remarkable early observation 🔗

Perhaps the most striking moment in Aristotle’s writings on dreams is his brief but remarkably prescient reference to what we now call lucid dreaming. He notes that sometimes, even while asleep, a part of the dreamer’s consciousness recognises that what is appearing is only a dream. In Western literature, this may be the first documented mention of lucid dreaming – the phenomenon of becoming aware that one is dreaming during ongoing sleep – appearing in Aristotle’s Parva Naturalia treatise On Dreams.

This observation was remarkable because it pointed to something the later neuroscience of dreaming would confirm: that consciousness during sleep is not uniform or simply absent. Modern research shows that during REM sleep, the brain generates vivid, sensorimotor hallucinatory experiences that follow a narrative structure, while the dreamer remains largely disconnected from the environment. The question of whether dreaming involves bottom-up sensory activation or top-down cognitive synthesis is one that, as researchers now note, was being asked in some form since Aristotle’s time.

Dreams as a window into reality and consciousness 🔗

For Aristotle, the study of dreams was not a curiosity separate from his broader philosophical project – it was directly connected to understanding what consciousness is and how the mind relates to the world. The dreaming state, precisely because it suspends ordinary sensory contact with reality, reveals the structure of the mind’s imaginative and perceptual capacities in a way that waking life may obscure.

When we dream, we are not in touch with external reality, yet we have vivid, convincing experience. This means that experience – consciousness itself – does not require direct contact with the external world to operate. The mind generates its own world using the materials of past perception. This is a philosophically profound point, and it anticipates modern discussions about the relationship between perception, imagination, and consciousness that contemporary philosophy of mind and sleep research are only beginning to fully work out.

Aristotle also believed, as his work in De Divinatione per Somnum suggests, that the body’s physical condition influences dream content in ways the dreamer may not consciously understand. A person’s emotional state, physical health, and unresolved tensions from waking life all leave traces in the imagination that resurface during sleep. In this respect, his account prefigures later psychological theories – from Freud’s view of dreams as expressions of unconscious desires to cognitive theories that see dreaming as a process of memory consolidation and emotional integration.

Aristotle’s legacy in the philosophy of mind 🔗

In both De Anima and the Parva Naturalia, Aristotle investigates the phenomena common to soul and body, asking whether all psychological states are also material states of the body – a question that remains central to the philosophy of mind today. His non-dualistic framework, which refuses to treat the mind as a ghost inside a machine, continues to inform both philosophical and scientific approaches to consciousness.

His specific account of dreaming – as a natural, biologically grounded phenomenon involving imagination, residual sensory movement, and the partial suspension of rational judgment – provided a model that influenced thinkers from the medieval Aristotelians to Thomas Hobbes in the 17th century, and was cited by Sigmund Freud as the first account to recognise that dreams follow the laws of the human spirit rather than supernatural manifestation. The fact that contemporary researchers in psychology, psychophysiology, and neurobiology have found many of Aristotle’s observations on sleep and dreaming to be consistent with experimental evidence is a testament to the quality of his naturalistic inquiry.

What Aristotle gave us was not just a theory of dreams, but a framework for thinking about mind as something deeply embedded in the living body – active even in sleep, constructing experience from the inside, and offering, through that very construction, clues about what it means to be conscious at all.

What do you think? If dreams are, as Aristotle argued, built entirely from the raw material of our waking experiences, what does that suggest about the boundaries between perception and imagination in our everyday conscious life? And if the body’s physical state shapes the content of dreams without our awareness, how much of what we experience as “mental” is actually rooted in the biological conditions of the body?

References

1. https://www.britannica.com/biography/Aristotle/Philosophy-of-mind
2. https://www.researchgate.net/publication/304101931_Aristotle's_Theory_of_'Sleep_and_Dreams'_in_the_Light_of_Modern_and_Contemporary_Experimental_Research
3. https://faculty.washington.edu/smcohen/320/psyche.htm
4. https://ndpr.nd.edu/reviews/the-undivided-self-aristotle-and-the-mind-body-problem/
5. https://e-logos.vse.cz/pdfs/elg/2014/01/17.pdf
6. https://brill.com/display/book/9789004506091/BP000015.xml?language=en
7. https://dreamhawk.com/dream-encyclopedia/aristotle-on-dreams/
8. https://en.wikipedia.org/wiki/On_Dreams
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC6451677/
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC2814941/
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12. https://plato.stanford.edu/entries/aristotle-psychology/