[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:

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


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

First published: 21/11/2019

[2.1.1] The Epicurean Mind

“Epicurus’ (341-271 BC) epistemology is resolutely empiricist and anti-skeptical. All of our knowledge ultimately comes from the senses, thinks Epicurus, and we can trust the senses, when properly used…
Epicurus says that there are three criteria of truth: sensations, ‘preconceptions,’ and feelings.”
The UML Use Case diagram below depicts the Epicurean model of the human mind:

The epicurean mind
FacultyRelated Use Case
PERCEPTIONExperience Sensation through PERCEPTION: “…all sensations give us information about the world, but that sensation itself is never in error, since sensation is a purely passive, mechanical reception of images and the like by sense-organs, and the senses themselves do not make judgments ‘that’ the world is this way or that. 
Instead, error enters in when we make judgments about the world based upon the information received through the senses.”
MINDUse Preconception: “…we have certain ‘preconceptions‘–concepts such as ‘body,’ person,’ ‘usefulness,’ and ‘truth’–which are formed in our (material) minds as the result of repeated sense-experiences of similar objects. Further ideas are formed by processes of analogy or similarity or by compounding these basic concepts. Thus, all ideas are ultimately formed on the basis of sense-experience.”
MINDUse Feelings: “…Feelings of pleasure and pain form the basic criteria for what is to be sought and avoided..”

The source of all citations and more about the topic in: Tim O’Keefe, “Epicurus“, Internet Encyclopedia of Philosophy

First published: 01/03/2019

  • 06/02/2019: changed Use Case names
  • 28/13/2019: added Use Memory