Parva Naturalia (Short Treatises on Nature)

Summary

The Parva Naturalia, 'little works on nature', is the medieval Latin name for a group of short treatises in which Aristotle carries the theory of the soul from On the Soul (De Anima) into the body. His opening sentence announces the plan: having considered the soul by itself, he will now examine the activities that belong to soul and body together, such as sensation, memory, passion, appetite, sleep and waking, youth and age, breathing, life and death. The library's text, from the Oxford translation, contains the treatises On Sense and the Sensible, On Memory and Reminiscence, On Sleep and Sleeplessness, On Dreams, On Prophesying by Dreams, On Longevity and Shortness of Life, and a combined treatise On Youth and Old Age, On Life and Death, On Breathing. On Sense examines the organs of the five senses and their objects, rejecting Plato's and Empedocles' theory that the eye sees by sending out fire, and arguing that hearing, because it carries speech, contributes most to learning. On Memory distinguishes memory, a lasting image of something perceived and marked as past, from recollection, an active search through a chain of associated movements, which Aristotle thinks only human beings perform. He compares memory to the impression of a seal and explains why the very young, the very old, and people too quick or too slow remember badly. On Sleep calls sleep a seizure of the primary sense faculty seated in the heart, brought on by vapours rising from digested food and cooled in the head, and argues that it exists for the preservation of the animal. On Dreams treats dreams as residual movements of earlier perceptions, noticed when waking sense falls silent, and explains how emotion and fever make faint likenesses seem real. On Prophesying by Dreams cautiously concludes that most apparently prophetic dreams are coincidences, though some may be signs of bodily conditions or causes of later actions, and that dreams are not sent by God, since animals also dream. The last treatises connect length of life, ageing and death with the natural heat of the heart and with the cooling provided by lungs or gills, and survey the breathing of many kinds of animals. For readers interested in medicine, the collection is one of the founding texts of the physiology of sleep, memory and ageing. Aristotle opens and closes it by noting that natural philosophers and philosophically minded physicians meet on the ground of health and disease, and the work shaped Galenic, Arabic and medieval university medicine. Its physiology, centred on the heart rather than the brain, is mistaken, yet its careful descriptions of memory, recollection, and the way emotion distorts perception remain worth testing against experience.

Plot or Argument

• On Sense and the Sensible: organs and objects

  After setting out the programme of the whole collection (Part 1), Aristotle ranks sight as most useful for necessities and hearing as most useful for intelligence, so that the blind from birth are more intelligent than the deaf and dumb. He argues that the eye is made of water rather than fire, criticising the Timaeus and Empedocles (Part 2), then analyses colour, savour and odour (Parts 3-5) and asks whether two stimuli can be perceived at once (Part 7).

• On Memory and Reminiscence: the seal and the search

  Memory belongs to the primary sense faculty and is of the past, marked by a sense of time elapsed (Part 1). It is like the impression a signet leaves, which fails to take in those whose constitution is too fluid or too hard. Recollection is a deliberate hunt through associated movements, a kind of inference proper to human beings, and once started it can run on uncomfortably, especially in the melancholic (Part 2).

• On Sleep and Sleeplessness: why animals sleep

  Sleep and waking belong to the same faculty, since sleep is the privation of waking (Part 1). Sleep is an incapacity of the primary sense organ, whose seat in blooded animals is the heart (Part 2), caused by vapour from digestion that rises and is cooled in the brain; this explains drowsiness after meals, in infancy and in certain illnesses, and Aristotle compares sleep to an epileptic seizure (Part 3).

• On Dreams: images left behind

  Dreaming is the work of the imaginative side of the perceptive faculty (Part 1). Sense impressions persist after their objects are gone, like after-images of the sun, and emotion makes us take slight likenesses for real things, as when a feverish patient sees animals in the patterns on a wall (Part 2). In sleep, as the blood settles, these residual movements appear, clear or distorted (Part 3).

• On Prophesying by Dreams: cause, sign or coincidence

  Aristotle refuses either to dismiss or to accept predictive dreams wholesale. A dream may be a sign of a bodily state the waking person cannot yet feel, which is why physicians attend to dreams, a cause of a later action, or a mere coincidence (Part 1). Since animals dream and since vivid predictive dreams come to ordinary rather than wise people, dreams are not sent by God, though nature itself is divinely ordered (Part 2).

• Longevity, youth and age, life and death, breathing

  On Longevity asks why some plants and animals live long and others briefly, relating life-span to moisture, warmth and size. The final treatise locates the nutritive soul in the heart, explains life as the preservation of natural heat and death as its failure, describes the painless death of old age as a feeble flame going out, and surveys respiration and gills, criticising Democritus, Anaxagoras, Diogenes and the Timaeus before closing on the meeting of natural science and medicine.

Characters

• Plato (the Timaeus), interlocutor

  Criticised for the theory that vision is a ray of fire leaving the eye and for his account of breathing.

• Empedocles, interlocutor

  Quoted at length for his simile of the eye as a lantern, then refuted.

• Democritus, interlocutor

  Praised for holding that the eye is watery but faulted for reducing all senses to touch and for his theory of breathing.

• Anaxagoras and Diogenes of Apollonia, interlocutors

  Natural philosophers who held that fish breathe air drawn from water; Aristotle argues their theories are untenable.

• The physicians, allied inquirers

  Practitioners who base medicine on natural philosophy and who, Aristotle reports, pay attention to dreams as signs of bodily states.

Lessons

• Memory as the seal, recollection as the hunt

  Aristotle distinguishes the passive persistence of an image from the active search by which we recover it, noting that slow people often have good memories while the quick are better at recollecting. His account of association, moving from one thing to what is like it, opposite to it or next to it, is the root of much later psychology. Students can test it against their own study habits.

  • What is the difference between remembering and recollecting in On Memory, Parts 1-2?
  • Why does Aristotle think the very young and very old remember poorly?
  • Which of Aristotle's tips for recollecting (starting points, order, association) do you already use when studying?

• Why the frightened see what they fear

  In On Dreams, Part 2, Aristotle observes that the angry, the desirous and the frightened are easily deceived, and that the more intense the passion, the less resemblance is needed to produce an illusion. The feverish patient who sees animals in the wall pattern is his example. The lesson is moral as well as physiological: passion clouds judgment, and self-command helps us see truly.

  • What examples does Aristotle give of emotion distorting perception?
  • How does his explanation of the feverish patient's vision work?
  • Where in literature or in your own life has strong feeling made you misread a situation?

• Weighing a prophetic dream without credulity or contempt

  On Prophesying by Dreams begins by saying the subject should be neither despised nor easily believed. Aristotle then sorts dreams into causes, signs and coincidences, and concludes that they are not sent by God, while still calling nature divinely ordered. Christian readers can admire his discipline while noting that Scripture records God speaking through dreams to Joseph, Daniel and others, a possibility Aristotle's reasoning does not consider.

  • What are the three ways, according to Aristotle, that a dream can be related to a later event?
  • Why does the fact that animals dream lead him to deny that God sends dreams?
  • How would a Christian reader answer Aristotle's argument, given the dreams of Joseph in Genesis or in Matthew?

• Old age as a flame burning low

  The treatise On Youth and Old Age, On Life and Death explains life as the preservation of the heart's natural heat and old age as its gradual exhaustion, so that death in old age comes gently, like a small flame going out. Though the physiology is mistaken, the image shaped centuries of medical thinking about ageing and invites reflection on how to regard the end of life.

  • Why does Aristotle think death in old age is painless?
  • What does the comparison of life to a flame capture well, and what does it leave out?
  • How does this account of ageing compare with the treatment of old age in Ecclesiastes 12?

Context

These treatises sit between On the Soul and Aristotle's large biological works (History of Animals, Parts of Animals, Generation of Animals), and they cross-refer to both. They draw on and argue with the medical writers of the Hippocratic tradition and with natural philosophers from Empedocles to Democritus, and they assume Aristotle's view that the heart, not the brain, is the seat of sensation and life, a view that the Alexandrian anatomists Herophilus and Erasistratus would soon challenge.

Composition

The treatises probably date from Aristotle's later teaching, perhaps during or around his time in Assos and Lesbos and in the Lyceum period (335-322 BC), so the range c. 350-330 BC is approximate. They were not written as one book; the collective title Parva Naturalia was given by medieval Latin translators. The library's text is the Oxford translation, by J. I. Beare (On Sense to On Prophesying by Dreams) and G. R. T. Ross (the remaining treatises), transcribed by the MIT Internet Classics Archive with its own Part numbers.

Reception

The treatises were paraphrased by Themistius, used by Galen, and studied by Avicenna and Averroes, whose epitome of the Parva Naturalia was widely read. Albertus Magnus and Thomas Aquinas commented on On Sense and On Memory, and Aquinas drew on the memory treatise in his teaching on prudence. In medieval universities the works formed part of the arts curriculum and informed medical theories of sleep, dreams and the 'internal senses'; the memory treatise later shaped the Renaissance art of memory. It was included in the Great Books of the Western World (2nd ed., 1990), volume 7.

Comparisons

• De Anima

  On the Soul defines the soul and its faculties in general; the Parva Naturalia applies that definition to particular bodily activities, so the two should be read in sequence, with De Anima III on imagination as the bridge to the dream treatises.

• Confessions

  Augustine's Book X marvels at the 'fields and spacious palaces' of memory and turns the inquiry toward God, while Aristotle locates memory in the bodily sense faculty; reading both shows two ancient accounts of the same experience pursued to different ends.

• Hippocratic Writings

  The Hippocratic Regimen IV interprets dreams as signs of bodily states, the medical practice Aristotle has in view when he says physicians attend to dreams; Aristotle supplies a theory of why such signs might work.

• The Interpretation of Dreams

  Freud opens his book by surveying earlier literature and cites Aristotle's view that dreams are the mental activity of the sleeper and can magnify slight bodily sensations; both reject divine origin, but Freud reads dreams as wishes, Aristotle as residual sense impressions.

• Galen: Selected Works

  Galen keeps much of Aristotle's physiology of heat and breath but follows the Alexandrian anatomists in placing sensation and thought in the brain rather than the heart, the decisive correction to the Parva Naturalia.

• The Anatomy of Melancholy

  Burton's treatment of melancholy, sleep and disturbed dreams draws on the Aristotelian tradition, including the idea, found here, that the melancholic are moved powerfully by images and recollect compulsively.

Quotes

Medical Lens

Medical relevance was raised from none to high because the treatises themselves deal directly with sleep, dreams, memory, epilepsy, the melancholic temperament, fever delirium, ageing and death, and twice address the relation of natural philosophy to medicine. Aristotle's cardiocentric physiology (sensation seated in the heart, sleep caused by digestive vapours cooled in the brain) was rejected by Galen's brain-centred account, but his descriptions of association in recollection, of emotion-driven illusions, and of dreams as possible early signs of illness entered Galenic, Arabic and medieval medicine. His 'atrabilious' or melancholic persons belong to the humoral framework; any correlation with modern diagnoses is a reading, not a fact.

• On Sense and the Sensible, Part 1

  Programme of the collection: the physical philosopher should know the first principles of health and disease, and philosophical physicians build their medicine on natural science.

  Physicians Doctors Ancient Medicine Mind Body
• On Memory and Reminiscence, Parts 1-2

  Memory as an impression like a seal; defective memory in the very young, the very old, and those too quick or slow; recollection that persists uncomfortably in persons of melancholic temperament.

  Dementia Memory Aging Senescence Melancholia Depression Humoral Medicine
• On Sleep and Sleeplessness, Parts 2-3

  Sleep as an incapacity of the primary sense organ in the heart, caused by vapour from digestion; sleepiness after meals, in infants, in fever and lethargy; sleep compared to epilepsy; the atrabilious not given to sleep.

  Sleep Insomnia Epilepsy Seizures Fever Infection Humoral Medicine
• On Dreams, Parts 2-3

  After-images and persistence of sensation; illusions in anger, desire, fear and fever delirium; unhealthy, confused dreams in the atrabilious, the feverish and the drunk.

  Dreams Nightmares Fever Infection Altered States Melancholia Depression
• On Prophesying by Dreams, Parts 1-2

  Physicians attend to dreams because slight bodily movements unnoticed by day may become perceptible in sleep; melancholic and excitable temperaments have vivid and apparently prophetic dreams.

  Dreams Nightmares Physicians Doctors Melancholia Depression
• On Youth and Old Age, On Life and Death, On Breathing, Parts 23 and 27

  Death as extinction of the heart's natural heat; painless death in old age; diseases that harden the lung or cause fever accelerate breathing; closing remarks on the shared ground of physicians and natural scientists.

  Aging Senescence Death Dying Fever Infection Physicians Doctors

Creative Prompts

• Classroom

  Keep a one-week log of times you tried to recall a name or fact, noting where you started and what chain of associations led you to it, then compare your log with Aristotle's account of recollection in On Memory, Part 2.

• Dialogue

  Write a conversation between a Hippocratic physician who uses dreams to diagnose illness and Aristotle, who explains why some dreams are signs, some causes and most mere coincidences.

• Essay

  Aristotle argues that dreams are not sent by God because animals dream too. Evaluate the argument, taking account of the dreams in Genesis 37-41 or Matthew 1-2.

Further Reading

• On the Soul (De Anima), Aristotle

  The general theory of soul and its faculties that the short treatises apply.

• Regimen IV (On Dreams), Hippocratic writers

  The medical tradition of reading dreams as signs of the body's condition.

• Commentary on Aristotle's On Sense and On Memory, Thomas Aquinas

  Aquinas' exposition of the first two treatises.

• Aristotle on Memory, Richard Sorabji

  Translation and philosophical commentary on On Memory and Reminiscence.

• The Art of Memory, Frances A. Yates

  Traces how Aristotle's memory treatise fed medieval and Renaissance memory arts.