[2.1.2] Epicurean Cosmology

Epicurus (341-271 BC) held that the universe is compound exclusively of two primary constituents:

  • eternal, ever-moving and colliding atoms, grouped in moving macroscopic objects [bodies]
  • empty space
  • human soul is made of special soul atoms.

The OntoUML diagram below presents the structure of the epicurean universe:

ClassDescriptionRelations
Universe“Epicurus held that the elementary constituents of nature [universe] are undifferentiated matter, in the form of discrete, solid and indivisible particles (“atoms”) below the threshold of perception, plus empty space, that is, the complement of matter or where matter is not…
an infinite number of solid and therefore indivisible atoms of finitely many kinds, such as Epicurus’ theory provides, are enough to avoid the possibility of the universe crumbling into nothing.”
The universe is infinite end eternal; more than that, more universes can co-exist.
MacroscopicObjectMacroscopic objects [or bodies], of course, do not move at a uniform and very great speed… In the case of compound objects that are completely at rest, the resultant of internal atomic motions is zero, relative, at least, to the earth, which may have an average motion of its own.”is exclusive part of the Universe
Atom“Epicurus held that the elementary constituents of nature are undifferentiated matter, in the form of discrete, solid and indivisible particles (“atoms”) below the threshold of perception… All secondary properties, such as color and taste, will be explained as epiphenomena of atomic combinations… atoms can come in different shapes and sizes (though never large enough to be seen) “
Atoms are eternal.
is exclusive member of the MacroscopicObject
EmptySpaceempty space, that is, the complement of matter or where matter is not… Void must exist, in turn, if bodies are to be able to move, as they are seen to do. Thus motion is the counterwitness to the non-existence of void — an indirect argument is required since one cannot perceive empty space.”is contained in the Universe
HumanHuman beingis MacroscopicObject
SoulAtomsThe soul “consists of atoms: first, there is nothing that is not made up of atoms and void.., and second, an incorporeal entity could neither act on nor be moved by bodies, as the soul is seen to do (e.g., it is conscious of what happens to the body, and it initiates physical movement). Epicurus maintains that soul atoms are particularly fine and are distributed throughout the body, and it is by means of them that we have sensations (aisthêseis) and the experience of pain and pleasure, which Epicurus calls pathê (a term used by Aristotle and others to signify emotions instead). Body without soul atoms is unconscious and inert, and when the atoms of the body are disarranged so that it can no longer support conscious life, the soul atoms are scattered and no longer retain the capacity for sensation. There is also a part of the human soul that is concentrated in the chest, and is the seat of the higher intellectual functions. The distinction is important, because it is in the rational part that error of judgment enters in.”  is Atom; is exclusive member of the Human
NotSoulAtomsNot soul atom: other atom than soul atoms in the human body.is Atom; is exclusive member of the Human

Sources

  • All citations from: Konstan, David, “Epicurus”The Stanford Encyclopedia of Philosophy (Summer 2018 Edition), Edward N. Zalta (ed.)

First published: 21/11/2019

[1.3.14] Aristotle on Cosmology

On the Heavens (De caelo) is Aristotle’s (384-322 BC) main cosmological work. In the elaboration of his astronomical theories, he relies on concepts like motion [1.3.13], elements [1.3.12], hylomorphism [1.3.5].
The following OntoUML diagram shows the main classes in this model:

Aristotle’s cosmology
ClassDescriptionRelations

UnmovedMover
“In the De caelo Aristotle posits an unchanging intelligent being that exists beyond the heavens, enjoying there ‘the best and most selfsufficient life’ (1. 9, 279121-2). In Physics 8 and Metaphysics this entity becomes the Prime Unmoved Mover, ultimately responsible for all movement, change, and generation in the universe…
The Prime Mover is the unmoved mover (see [1.3.13]) of the sublunary elements. So it seems natural to assume that the self-mover responsible for the motion of fire and earth has the Prime Mover as its unmoved part. The Prime Mover moves the aether, and as we have seen, the aether moves the sublunary elements.” (Matthen, 2001)
moves Aether
ObjectObjects, according to Aristotle are primary existents, compounds of Matter and Form.
FormThe form is that which unifies the Matter into a single object, and which provides actuality. characterizes Object
MatterThe matter (substance) is that which persists in the object, and which provides potentiality.
Universe “in the De caelo Aristotle treats of the universe as a single individual substance [object] with form and matter… ‘Since the universe is perceptible, it is an individual thing [object]; for every perceptible thing exists in matter…
Aristotle’s assertion, in De caelo 1. 9, that the universe is individual occurs in the context of his rejecting the atomist’s many-worlds thesis: ‘Such a plurality is impossible if this world is made from the entirety of matter, as it is’. In general, form admits of plural instantiations, he concedes. However, when a form is instantiated in all matter, it can be instantiated only once.” (Matthen, 2001)
subkind of Object
CelestialBody Celestial Bodies are the stars, the planets, the Sun, and the Moon. These are the most perfect realities, composed of unperishable and incorruptible aether.subkind of Object; component of the Universe; located on CelestialSphere
AetherAether is the matter/element for celestial bodies, moved by the Prime Unmoved Mover. It is a perfect element, not generated, and not corruptible.subkind of Matter; contained in CelestialBody; moves Element
CelestialSphereThe Celestial Bodies, are located on the (perfect) celestial spheres. The stars are fixed on their own sphere; each planet, the Sun and the Moon circulates on its own sphere. This movement is circular, regular and continuous.
SublunaryBodySublunary bodies are located under the Celestial Sphere of the Moon. They include the Earth – the center of the universe, ad all the natural (e.g. minerals, living beings, humans) and man-made objects (e.g. houses, statues) in the Earth.
Sublunary bodies can move naturally – depending on the Nature of the Sublunary Matter they are composed of -, and can have forced movements.
subkind of Object; component of the Universe
SublunaryMatter Sublunary matter, at the bottom level, is composed of a mix of the four elements, is generated and corruptible.contained in SublunaryBody
Element“Aristotle believes that everything is made of earth, air, fire and water. These elements are defined by their possession of one of each of the two fundamental pairs of opposites, hot/cold and wet/dry. Aristotle also thinks that these elements can change into one another” (Ainsworth, 2016)subquantity of the SublunaryMatter
Water; Earth; Fire; Air Water; Earth; Fire; Air are the elements of sublunary bodies.
They all have their Nature, e.g.
– Fire and Air tend to move upwards;
– Water and Earth tend to move downwards.
subkinds of Elemenet

Sources

  • Ainsworth, Thomas, “Form vs. Matter“, The Stanford Encyclopedia of Philosophy (Spring 2016 Edition), Edward N. Zalta (ed.)
  • Bodnar, Istvan, “Aristotle’s Natural Philosophy”The Stanford Encyclopedia of Philosophy (Spring 2018 Edition), Edward N. Zalta (ed.)
  • Matthen, Mohan,The Holistic Presuppositions of Aristotle’s Cosmology”, in Oxford Studies in Ancient Philosophy 20:171-199 January 2001

First published: 3/10/2019
Updated: 7/12/2021