On Sleep and Sleeplessness
- Language:
- English
- Status:
- Complete work
- Authorship:
- Written by the author
- Condition of the text:
- No scanning noise detected (automatic measure over the whole text, not checked by hand)
- Extent:
- ~5,680 words · 27 passages
Cite this work
- APAAristotle. (n.d.). On Sleep and Sleeplessness. Digital reproduction: SigPhi. https://sigphiai.com/en/works/aristotle/on-sleep-and-sleeplessness
- MLAAristotle. On Sleep and Sleeplessness. Digital reproduction, SigPhi, https://sigphiai.com/en/works/aristotle/on-sleep-and-sleeplessness.
- ChicagoAristotle. On Sleep and Sleeplessness. Digital reproduction, SigPhi. https://sigphiai.com/en/works/aristotle/on-sleep-and-sleeplessness.
Reference to the edition that SigPhi reproduces: SigPhi is its digital reproduction, not its publisher. The edition's year is not in the metadata (hence "n.d."), and the translator appears only when recorded.
What it is about
What sleep is, why it is needed, and why the same organ both perceives and stops perceiving.
Context and history
Aristotle treats sleep as a necessary privation of perception, tied to digestion and the heat of the heart. The physiology is wrong; the question — why must a perceiving animal stop perceiving every day — is still open. Part of the Parva naturalia, the eight short works that continue the De anima by applying its theory to particular phenomena of the living body. They are transmitted as a group and read best together.
Editorial context, not a citable source: unlike the passages of the work itself, these statements cannot be checked against the corpus.
the evaporation upwards is excessive. Those [on the contrary] whose veins are large are, thanks to the easy flow through the veins, not addicted to sleep, unless, indeed, they labour under some other affection which counteracts [this easy flow]. Nor are the 'atrabilious' addicted to sleep, for in them the inward region is cooled so that the quantity of evaporation in their case is not great. For this reason they have large appetites, though spare and lean; for their bodily condition is as if they derived no benefit from what they eat. The dark bile, too, being itself naturally cold, cools also the nutrient tract, and the other parts wheresoever such secretion is potentially present i.e. tends to be formed . Hence it is plain from what has been said that sleep is a sort of concentration, or natural recoil, of the hot matter inwards [towards its centre], due to the cause above mentioned. Hence restless movement is a marked feature in the case of a person when drowsy. But where it [the heat in the upper and outer parts] begins to fail, he grows cool, and owing to this cooling process his eye-lids droop. Accordingly [in sleep] the upper and outward parts are cool, but the inward and lower, i.e. the parts at the feet and in the interior of the body, are hot.