Transcript Ancient and medival philosophy of dreams

Philosophy of Dreams and Sleeping:
Ancient and Medieval views
Markku Roinila
Greek philosophy
 Greeks followed the traditions of
Mesopotamia and Egypt in thinking that
dreams were of divine origin. Compare
Homeros’ Odyssey where there are two gates
from the underworld admitting dreams to
mortals, one of horn and one of ivory,
representing truthful and deceptive dreams.
Dream-oracles were common in Ancient
Greece.
 The ancient Greeks never spoke of having a
dream, but always of seeing a dream. Thus the
dreamer was a passive in the process – thus
the dreamer is receiving messages or vision
from Gods (the same was thought by
Romans).
 Widely discussed was the morality in dreams,
the consensus being that moral character had
an effect on the content of dreams.
 An introduction to Greek and Roman views
on dreaming: Joseph Barbera: “Sleep and
dreaming in Greek and Roman Philosophy,”
Sleep Medicine 9 (2008), pp. 906-910
The pre-socratics
 Influenced by Thales, early Greek philosophers tried to understand
natural phenomena in their own terms without the hypothesis of
Divine intervention although the Divine voice-tradition also
continued.
 The most well-known of the presocratics are the views of
Heraclitus “the obscure” (535-475 BC). He emphasized the
subjective nature of dreams in his phrase “for those who are awake
there is a single, common universe, whereas in sleep each person
turns away into his own private universe”. This can be interpreted
to say that a person's dream world was something created in their
own mind.
 The Pythagoreans seem to have supported the idea of Divine
origin of dreams as they believed the that the air was “full of souls”
capable of affecting dreams.
More presocratics
 Empedocles (490-430 BC)
thought that dreams depended
on the dreamer and described
sleep as occurring from a
moderate cooling of heat in the
blood with death being the
result of a total cooling.
 This view was followed by
Parmenides and Leucippus, the
first atomist, who also described
sleep as something that
happened to the body, and not
the soul, and which occurred
when ”the excretion of finetextured atoms exceed the
accretion of psychic warmth.”
Democritus
 Democritus of Abdera (460-370 BC) developed the first systematic and naturalist theory
of dreaming. He was an atomist, according to which the universe consisted of an infinite
number and variety of immutable (one cannot change it after it is created) atoms whose
continual motion and interaction were responsible for the varied and ever changing
nature of the world.
 According to Democritus, the universe consists of an infinite number of tiny atoms,
which interact and gather to constitute visible, ordinary objects. These objects emit a
continuous stream of images, or films, or effluences. Perception arises from the
impact of these images on the sensory organs, whereas thought occurs when images
penetrate the pores of the body, bypassing the senses, and directly act on the soul.
The direct impact of images on the soul is also the explanation of dreams. He states that
images can display all sorts of attributes of the objects which emit them. This is why we
can have dreams, for example, of other people thinking, feeling and acting.
”The eidola penetrate bodies through their pores and when they come up again cause people
to see things in their sleep; they come from things of every kind…but especially from
animals, because of the quantity of morion and heat they contain.”
 In addition, dreams are affected by each person’s psychic motions, desires, habits and
emotions. Basically emotions are, however, caused by external phenomena as the eidola
received from other persons contains traces of their attributes.
 Democritus was the most influential philosopher of dreams in the Ancient world
although today the views of Aristotle are much more valued.
Plato
 Plato (427-347 BC) followed mostly the divine tradition (for example, Charmides and
Socrates’ dream in Crito). Also, in the Phaedo, he tells how Socrates studied music and the
arts because he was instructed to do so in a dream.
 However, Plato also offered a naturalistic theory of dreaming in Timaeus. It is related to
his theory of vision which is a product of a non-burning, light-giving ”pure fire” which
streams out from the eyes and strikes external objects.
“When the cognate fire is gone at nightfall, the visual stream is cut off. For when it
encounters something different from itself, it is changed and quenched, as it is no longer of
the same nature as the adjoining air inasmuch as the air lacks fire. Therefore it stops seeing
and gives rise to sleep.” (Plato, Timaeus 45d3–7)
 Thus movement produced by this are transmitted back to the soul where visual
perception occurs. At night the ”external and kindred fire” departs with a subsequent
cessation of vision and a resultant induction of sleep.
 With the eyelids closed the ”internal fire” is directed inwards to equalize the ”inward
motions”. Where such equalizations occurs there is quiet sleep and where it does not,
there is dreaming. In addition, there can still be divination and when this happens, the
site of dream prophecy is the liver.
Psychological component of dreams
 In Republic Plato discusses the terrifying
content of dreams:
”…in all of us, even the most highly
respectable, there is a lawless wild beast
nature, which peers out in sleep.”
 Plato’s discussion sounds Freudian: in
dreams there is bestiality, even incest
which is normally repressed when
awake.
 The difference is that in Plato these are
uncovered while in Freud the desires or
wishes are disguised.
 Plato also uses dream fantasy to
chracterize his own enterprise in the
construction of an ideal state. Especially
the sexual roles are presented in this
manner. The ideal state is presented as
Socrates’ day-dream (458a).
Are we awake or sleeping?
 Plato formulates the essential metaphysical question of philosophy of dreaming
in Republic 476c2-d4:
”- As for the man who believes in beautiful things but not in the existence of
Beauty itself, nor is able to follow one who leads him to the knowledge of it, do
you think that he lives in a dream or in a waking state? Consider: is this not
dreaming, namely, whether asleep or awake, to think that likeness is not a likeness
but the reality which it resembles?
- I certainly think that the man who does this is dreaming.
- The man who, on the contrary, believes that there is such a thing as Beauty itself,
who can see both it and the things which share in it, and does not confuse the two,
does he seem to you to live in a waking state or in a dream?
- In a waking state certainly, he said.”
Plato is arguing that if we cannot see how the appearances are related to the forms,
we must be sleeping. Later Descartes, Hobbes and Malcom, for example, discuss
this same question from a different point of view.
Theaetetus (157e-158e)
 Socrates examines and argues against a
subjectivist doctrine of Protagoras who
holds that all appearances are true for the
subject to whom they occur. Socrates
mentions dreams, illusions, hallucinations,
delusions as counter-examples to this
theory.
 Socrates asks whether he and Theaetetus are
awake or asleep and argues that dreaming
illustrates his theory. If one cannot separate
between awaking and sleeping state, one
cannot argue that dreams are not true for
the sleeping subject. What is the criterion to
argue that the appearances of the waking
person are more true to the sleeping
person? The dream-objects are thus,
according to Protagoras, true to the
dreamer while Socrates opposes the view.
Aristotle was not intersted in this question.
Plato & moral questions in dreams
 Plato divided in the Republic the
soul into three different parts: the
desiderative, the spirited, and the
rational.
 According to him, a vicious person
is unable to restrain his sensual
desires in sleep because the rational
part of his soul is at rest.
 However, these desires do not
disturb a virtuous person in
sleep, since he has prepared
himself against them by arousing his
rational part and by soothing the
desiderative and spirited parts
before falling asleep.
Aristotle
 Provides the most systematic and
largest discussion of dreams and
sleeping in Ancient philosophy.
 Three essays on the topic:
1)
On Sleep andWaking (De somno et
vigilia)
2)
On Dreams (De Insomniis)
3)
On DivinationThrough Sleep (De
divination per somnum)
Litterature:
David Gallop: Aristotle: On Sleep and
Dreams (including essays,
introduction, notes)
Mika Perälä: Aristotle on the Perception of
Perception: Seeing, Remembering, and
Sleeping (Diss., HU 2010)
Rational approach
 Aristotle rejected the Platonic divination-doctrine. He began to study
dreams and the dreaming process in a rational way. In On Sleep and
Waking he identifies sleep and waking as diametrically opposed
phenomena characterized by the absence of perception. Dreams are a
sort of misperception and thus to be inherently deceptive in a way that
ordinary perception is not. Dreams are on non-existent things or
situations.
 “Waking and sleep belong to the same part of a living being, for they are
opposites, and sleep appears to be a kind of privation of waking” (On
Sleep and Waking, 435b25-7)
 In On Divination through sleep, he states, "most so-called prophetic
dreams are to be classed as mere coincidences, especially all such as are
extravagant," and later includes that "the most skillful interpreter of
dreams is he who has the faculty of absorbing resemblances. I mean that
dream presentations are analogous to the forms reflected in water."
Dreams & Perception
 On Dreams // Aristotle suggests that dreams are neither the work of judgement nor of
perception in an unqualified way. Instead, dreams are the work of perception, but only of
its imagining (phantastikon) capacity. Thus dreams are the work of imagination.
 What does this mean? Appearances or impressions that characterize dreams are the result
of the perceptual mechanisms being activated, but in the absence of external stimulation.
Thus when are having no external stimulation, our perceptual mechanisms produces the
phantasmas or imaginations we call dreams.
 Sensory stimulation in wakefullness produces ”movements” within the body (probably
bloodstream) which persists for a time after the external stimulation has ceased. Such
prolonged sense impressions may give rise to delayed or false perceptions in
wakefullness, particularly in emotional states or illnesses (compare illusions). These are
exactly those that give rise to dreaming. Later Hobbes had a similar doctrine (decaying
sense in Leviathan, ch. 2).
 Although Aristotle rejects the Platonian forms, he uses a similar method in arguing that
one is sleeping, saying that in dreaming ”what is like something is judged to be that very
thing” (461b29) Thus we think that the dream object is a real object. The dreaming
subject mistakes a mere likeness for a genuine sense-impression and believes to be
perceiving a real thing. But there cannot be judgement in dreams as there is no
perception and this explains the acceptance of strange phenomena in dreams.
On Dreams
”…It is plain that the movements arising from sense impressions,
both those coming from outside and those from within the body,
are present not only when people are awake, but also whenever
the affection called sleep comes upon them, and that they are
especially apparent at that time. For in day-time, while the senses
and the intellect are functioning, they are pushed aside or
obscured, like a smaller fire next to a larger one, or minor pains
and pleasures next to big ones, though when the latter cease, even
the minor ones come to the surface. By night, however, owing to
the inactivity of the special sense and their inability to function
because of the reversal flow of heat from the outer parts to the
interior, they are carried inward to the starting-point of
perception, and become apparent as the disturbance subsides.”
Dreams from blood
 Thus dreams are in fact the result of
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persistant sense impressions travelling
in the blood stream, activating
perception in the heart. Thus Aristotle
is trying to give a naturalistic theory of
dreams (he is joined in this by
Democritus and Lucretius).
This happens all the time, but it is much
more powerful during the sleep when
the normal perception is suspended.
As the stream of blood behaves
differently in different times, the
dreams may be life-like or bizarre.
Because judgement is suspended during
sleep, we accept bizarre elements in
dreams as normal.
Distinction between dreams and
hallucinations – the cause is the same,
but latter take place when awake.
More Physiological theory
 According to Aristotle, sleep and waking result from the disabling
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and activation of the body’s primary sense-organ, that is, heart.
Sleep is induced by by the “exhalations” of ingested food which
thickens and heat the blood, rising to the brain where the are
cooled before coalescing in the heart.
Similar effects are ascribed to soporific agents, states of fatigue an
certain illnesses.
Aristotle distinguishes sleep from temporary incapacities of
perception, such as fainting, and describes sleep as a form of
“seizure”.
With this theory Aristotle helped advance the theory that dreams
reflected a person's bodily health. It suggested that a doctor could
diagnose a person illness by hearing a dream that they had.
Hippocratic-Galenic-tradition
Aristotle’s essays influenced Ancient medicine and the later tradition.
 Hippocrates, the founder of modern medicine supported his theory, and
it is still practiced by some doctors of today. Dreams were seen to be
signs of our internal conditions in the Hippocratic tradition. It was
customary that a skillful physician interpreted dreams as part of his
diagnostic and prognostic practice.
 Galen of Pergamum, a Greco-Roman physician, picked up where
Aristotle had left off. A patient of his dreamed that his left thigh was
turned into marble and later lost the use of that leg due to palsy. A
wrestler, he had treated, dreamed that he was standing in a pool of
blood that had risen over his head. From this dream Galen concluded
that this man needed a bloodletting for the pleurisy which he
labored. By this means of treatment the man was cured.
“ … when the brain itself wishes to have rest on account of excessive
activity, it induces to the animal a natural sleep, and especially
whenever the nutritive capacity is in a position to take advantage of
abundant moisture in itself…Dreams indicate for us the condition of the
body. If someone sees a conflagration in sleep, he is troubled by yellow bile.
If he sees smoke or mist or deep darkness, he is troubled by black bile. And
a storm of rain indicates an excess of cold moisture, while snow, ice and hail
indicate cold phlegm” (Galen, De symptomatum causis)
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On Divination Through Sleep
 The belief that dreams have some significance is common and it does in fact make some
sense. But the idea that God sends us these dreams is absurd and if that is denied, there is
not much left in the belief of divination in dreams.
 Therefore the divination is really sign or cause of an event or co-incidences.
 Often dreams are signs of bodily condition.These signs are more easily noticed during
sleep because even small movements seem to be big because there is less information
from other senses.
 Dreams can be causes – we rehearse situations in dreams and that can affect our
subsequent action (compare the Threat Simulation Theory by Antti Revonsuo)
 Most dreams, however, are co-incidences. The predictions they include are very often not
fulfilled, especially in cases where the dreamer does not have the causal iniative.
 In these kind of cases movements of air or water towards sleeping persons. Aristotle
critisized the views of Democritus, arguing basically the same as above – movements are
more readily noticed during the night. Especially ordinary people are subject to these as
they respond more easily to external stimuli.
More Aristotelian views
 Aristotle thought that the external stimuli affects the content of the dreams. For
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example, if someone is feeling hot, one may dream that one is walking through fire.
Perhaps this can also be explained through blood stream – perhaps the blood would turn
hotter and affect the appearances which feature in the dreams.
In On Divination Through Sleep Aristotle rejects the view that dreams have predictive
power – foretelling of future events based on dreams are just co-incidences. However,
there are few exceptions.
The most important is that dreams act as early signs of medical illness. The physical
changes produced by such illnesses lead to movements or abnormal sensory impressions
from within, impressions that can be better observed during dreaming. The same view
(that dreams are indicative of humoral imbalance was held by Hippocrates and Galen).
It is usually held that dreams have no telelogical function in Aristotle (such as divination),
which is surprising as in Aristotle’s philosophy almost everything is teleological. There
are other views, too. See Mor Segev: ”The Teleological Significance of Dreaming in
Aristotle”, Oxford Studies in Ancient Philosophy, vol. 43 who discusses just the humoral
inbalance as something which the dreams can bring up and which could be seen as their
purpose.
According to Aristotle, animals do dream (for example, a dog whines while sleeping),
but the dream has no content (De Somno 1, 454a19-29)
Malcolm on Aristotle’s views
 Norman Malcolm: Dreaming
 For Aristotle, a dream is a certain sort of appearance presented to during sleep. In this is
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included the idea that the subject is aware of their dreaming, otherwise the dream would
not exist.Thus dream is a mental experience that occur during sleep.
Malcom argues that this idea is misguided. Our concept of dreaming is derived not from
any such experiences, but from the familiar practice of telling dreams when we wake up.
The waking report of a person is the only criterion to judge that the person has slept. In
addition, the report is the only criterion to discuss what the person has dreamed about.
Therefore there cannot be mistakes – one cannot remember wrongly one’s
dreams.Malcolm argues that it is absurd to think that the persons is aware while being
asleep.
If Malcolm is right, most of the traditional philosophical questions about dreams would
be misguided as dreams are usually seen as kind of movies inside one’s head, independent
of the waking state.
Problems for him: if animals dream, how can they report their dreams? Sleepwalking –
one can demonstrate that someone is sleepwalking although the person does not
remember this.
Remembering dreams
In De Somnio Aristotle asks whether it be the
case that people always dream when asleep,
but do not remember (453b19).
 He does not accept that people always
dream and that would be in contradiction
with his physical views.
 Aristotle is just arguing that our waking
memory should be able to distinguish dream
images from waking images. But of course
they can err.
 Gallop’s judgement: ”Malcolm was right to
give dreamer’s reports a special status in the
determination of what they have dreamt. But
he was wrong to suggest that waking
impressions or reports of dreams could not
be mistaken, or that for someone to be
properly said to have dreamt, nothing need
to have happened in sleep at all” (Gallop,
Aristotle On Sleep and Dreams, p. 56)
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Epicureans
 Epicurus (341-270 BC)
rejected the divinationtheory. Following
Democritus, he thought
dreams are caused naturally
by the effluences or films
penetrating the sensory
organs.
 However, dreams are not
independent reality as
Democritus argued.
Lucretius
 Lucretius (94-49 BC) continued Epicurus’ theory in his On the Nature of the
Universe. The bizarre nature of dreams arises from the intermingling of surface
films in the air prior to their entering the mind. For example, the image of a
Centaur arises from the amalgamation of surface films from a man and a horse.
The succession of images in dreams may be affected by waking preoccupations.
 Sleep is caused by the vital spirit (the soul atoms diffused throughout the body)
becoming bombarded from without by the air to which it is exposed and from
within by respiratory motions. As a result the vital spirit is fragmented with
part of it ”forced out and lost” and part of it ”compressed and driven into the
inner depths”. The result is a weaking of the limbs and loss of senescence. It is
the part of the spirit forced inward that prevents outright death, with its
rekindling producing wakefullness.
“In principle, sleep occurs when the power of the spirit is scattered around the
body, and part has been expelled and gone away, and part is compressed and has
retreated into the innermost. For only then the limbs loosen and relax. (Lucretius,
De rerum natura IV.916–919)
The Stoics & Cicero
 Cicero (106-43 BC): On divination – discusses the divinatory power
of dreams and other forms of divination in the Ancient world such
as astrology, haruspicy (predicting from remains of sacrified
animals) and augury (predicting from omens and signs).
“Posidonius maintained that people dream under the influence of gods
in three ways. First, the soul foresees by itself because it bears affinity
to the gods. Secondly, the air is full of immortal souls in which what
one might call distinctive marks of truth are visible. Thirdly, the gods
themselves converse with people when they are asleep.” (Cicero, De
divinatione 1.64)
 Cicero argues that the Stoics, such as Chrysippus (280-207 BC) or
Posidonius (153-51 BC) supported the divination view – thus
dreams represents connection with Gods.
 He follows Aristotle in showing that the predictions in dreams are
often co-incidences.
 Cicero rejects the view of Democritus and argues that dreams are
the result of ”an intrinsic internal energy”, in other words
slackening of the tension in the pneuma [pneuma makes an animal
capable of perception and movement].
 An active cognitive component: various memories and daytime
preoccupations come to bear on the mind during sleeping.
Roman philosophers
 The Oneirocriticon or The Interpretation of Dreams by the Roman
Artemidorus (c. AD 150) is the first comprehensive book on the
interpretation of dreams. In this five-volume work, Artemidorus
brought out the idea that dreams are unique to the dreamer. He
believed that it was the person's occupation, social status and health
would affect the symbols in a dream.The interpretations were often
extremely strange.
 Macrobius (late 3rd century AD): Commentary of the Dream of Scipio.
Macrobius classifies dreams into five cathegories: 1) enigmatic dream 2)
prophetic vision 3) oracular dream (oracle-like dream) 4) nightmare 5)
apparation (quasi-perceptual). The first three are predictative, the latter
two not. Nightmares are caused by mental and physical distress or
anxiety by future and apparations are close to lucid dreaming.
Medieval philosophy of dreams
 The Ancient thinkers formulated
the basic ideas of dreaming – one
can even say that it took until the
neuroscience until the questions
changed. Thus the medieval
philosophers continued along the
same lines.
 Macrobius was thought to be the
leading authority on dreams in the
middle ages. This was probably
because he supporte the divinationview which was compatible with
the scholastic christian philosophy.
 Another important influence was
the Aristotelian physiology of
dreams.
Prelude: Augustinus
 Church Father St. Augustine is in fact part of Ancient world, but as he is the first
Christian thinker who wrote about dreams, I will discuss him here.
 Augustinus is foremost known from the moral problem of dreams: sinful
content in dreams (Confessions, book X) which we talked about earlier
 Another quote: ”A question sometimes arises about the consent given by those
who are asleep when they think they have sexual intercourse either contrary to
their good resolutions or against what is lawful. This does not happen unless
there is something that we also though while awake, not by consenting to an
opinion, but in a way in which we also speak of such things for some reason” (De
genesi ad litterarum XII.15.31)
 Augustinus is following the Greek tradition: good moral character produces
better dreams. We can battle against sinful dreams by purifying our thoughts
and desires while awake with the help of God.
Sleep and digestion
 A new theme in the history of philosophy of dreams is the idea that the origin of sleep in
corporeal processes is related to digestion.
 This view was included in the medical treatise called Pantegni which was the most used
in Western Europe.
 In the treatise the vapours of digestion rise to the brain as the cause of termination of
the sensory operations in sleep. The theory has some similarities to Aristotle’s
physiological theory, but this theory was explained on a brain-centered view of
perception instead of heart-centered view of Aristotle.
 However, Thomas Aquinas argued that there are two organs related to sleep: brains and
heart and the definition of sleep depends on which one is considered central.
Brain-centered view:
”This fine and sweet fume ascends from digestion and gently touches the brain and fulfils its
small cavities so that all its activities are tempered down. This is sleep. In this state all
powers of the soul cease to act and only the natural power is active, its acts more
intensively when it is not preventedby nature. The inner soul which has excluded all
functions of the senses presents to itself past, present and future things. These are
dreams.” (William of Saint-Thierry, De natura corporis et animae I.11-12.)
Jean Buridan on causes of sleep(heart-centered view)
”Sleep comes as follows: when one has eaten, the food is heated and digested by
heat which originally comes from the heart. This heating makes some vapours
come from the food. Because of its warmth and fineness, the vapours ascend
into the head and then, because of the coldness of the brain, they become colder
and coarser and, therefore, they turn naturally back downwards. When they
meet the heat of the heart they are diffused to exterior parts of the body and
they push the heart of the heart and the spirit to the seat intensifying the heat in
the digestive area so that the digestion of food will be completed.” (De somno et
vigilia q. 5)
 In this theory the brains have only a cooling function in sending the digestive
vapours back down towards the heart. The actual ceasing of the sensory
operations takes place when the internal heat and sensory spirits do not flow
from the heart to the sense organs as in waking state.
Types of dreams
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Anonymous treatise De spiritu et anima, based on Macrobius’s
theory distinguishes between five types of dreams:
Oracular saying (in dream some authority (father, priest, God)
says that something is to take place, something is to be done etc.)
Vision (something occurs exactly as it had happened in a dream)
Dream (something enveloped in figures which cannot be
understood without interpretation)
Nightmare (something has worried a waking man and return to
him when he is asleep)
Apparition (one has barely begun to sleep, and still thinks he is
awake; sees men rushing down upon him or sees differing forms
wandering about, which may be either pleasing or disturbing.
Character and physiology
 Everyone dreams according to
one’s pursuits, and the skills of
individual arts recur in dreams as
they are imprinted in the mind.
 Dreams differ according to one’s
infirmities. They also vary
according to the diversity of
one’s customs and humors. The
sanguine dreams different
dreams than the choleric,
phlegmatic or melancholic.
 Others see red and coloured
dreams, while melancholics
dream in black and white
Dreaming and prophecy
 Thomas Aquinas (Questiones
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disputatae de veritate 12.3)
Two kinds of prophecy: natural and
supernatural
When person is sleeping, we call
this kind of dream apparition and
the person is awake, a prophecy is
vision.
In both cases the soul is kept away
completely or partially by
phantasms.
In vision there is need to understand
while in apparition we just
experience the prophecy