Get Hylomorphism essential facts below. View Videos or join the Hylomorphism discussion. Add Hylomorphism to your PopFlock.com topic list for future reference or share this resource on social media.

Hylomorphism (or hylemorphism) is a philosophical theory developed by Aristotle, which conceives being (ousia) as a compound of matter and form. The word is a 19th-century term formed from the Greek words hyle, "wood, matter", and , morph?, "form".

Matter and form

Aristotle defines X's matter as "that out of which" X is made.[1] For example, letters are the matter of syllables.[2] Thus, "matter" is a relative term:[3] an object counts as matter relative to something else. For example, clay is matter relative to a brick because a brick is made of clay, whereas bricks are matter relative to a brick house.

Change is analyzed as a material transformation: matter is what undergoes a change of form.[4] For example, consider a lump of bronze that's shaped into a statue. Bronze is the matter, and this matter loses one form (morphe) (that of a lump) and gains a new form (that of a statue).[5][6]

According to Aristotle's theory of perception, we perceive an object by receiving its form (eidos) with our sense organs.[7] Thus, forms include complex qualia such as colors, textures, and flavors, not just shapes.[8]

Substantial form, accidental form, and prime matter

Medieval philosophers who used Aristotelian concepts frequently distinguished between substantial forms and accidental forms. A substance necessarily possesses at least one substantial form. It may also possess a variety of accidental forms. For Aristotle, a "substance" (ousia) is an individual thing--for example, an individual man or an individual horse.[9] The substantial form of substance S consists of S's essential properties,[10] the properties that S's matter needs in order to be the kind of substance that S is.[11] In contrast, S's accidental forms are S's non-essential properties,[12] properties that S can lose or gain without changing into a different kind of substance.[13]

In some cases, a substance's matter will itself be a substance. If substance A is made out of substance B, then substance B is the matter of substance A. However, what is the matter of a substance that is not made out of any other substance? According to Aristotelians, such a substance has only "prime matter" as its matter. Prime matter is matter with no substantial form of its own.[14] Thus, it can change into various kinds of substances without remaining any kind of substance all the time.[15]

Body-soul hylomorphism

Basic theory

Aristotle applies his theory of hylomorphism to living things. He defines a soul as that which makes a living thing alive.[16] Life is a property of living things, just as knowledge and health are.[17] Therefore, a soul is a form--that is, a specifying principle or cause--of a living thing.[18] Furthermore, Aristotle says that a soul is related to its body as form to matter.[19]

Hence, Aristotle argues, there is no problem in explaining the unity of body and soul, just as there is no problem in explaining the unity of wax and its shape.[20] Just as a wax object consists of wax with a certain shape, so a living organism consists of a body with the property of life, which is its soul. On the basis of his hylomorphic theory, Aristotle rejects the Pythagorean doctrine of metempsychosis, ridiculing the notion that just any soul could inhabit just any body.[21]

According to Timothy Robinson, it is unclear whether Aristotle identifies the soul with the body's structure.[22] According to one interpretation of Aristotle, a properly organized body is already alive simply by virtue of its structure.[23] However, according to another interpretation, the property of life--that is, the soul--is something in addition to the body's structure. Robinson uses the analogy of a car to explain this second interpretation. A running car is running not only because of its structure but also because of the activity in its engine.[24] Likewise, according to this second interpretation, a living body is alive not only because of its structure but also because of an additional property: the soul, which a properly organized body needs in order to be alive.[25] John Vella uses Frankenstein's monster to illustrate the second interpretation:[26] the corpse lying on Frankenstein's table is already a fully organized human body, but it is not yet alive; when Frankenstein activates his machine, the corpse gains a new property, the property of life, which Aristotle would call the soul.

Living bodies

Some scholars have pointed out a problem facing Aristotle's theory of soul-body hylomorphism.[27] According to Aristotle, a living thing's matter is its body, which needs a soul in order to be alive. Similarly, a bronze sphere's matter is bronze, which needs roundness in order to be a sphere. Now, bronze remains the same bronze after ceasing to be a sphere. Therefore, it seems that a body should remain the same body after death.[28] However, Aristotle implies that a body is no longer the same body after death.[29] Moreover, Aristotle says that a body that has lost its soul is no longer potentially alive.[30] But if a living thing's matter is its body, then that body should be potentially alive by definition.

One approach to resolving this problem[31] relies on the fact that a living body is constantly replacing old matter with new. A five-year-old body consists of different matter than does the same person's seventy-year-old body. If the five-year-old body and the seventy-year-old body consist of different matter, then what makes them the same body? The answer is presumably the soul. Because the five-year-old and the seventy-year-old bodies share a soul--that is, the person's life--we can identify them both as the body. Apart from the soul, we cannot identify what collection of matter is the body. Therefore, a person's body is no longer that person's body after it dies.

Another approach to resolving the problem[32] relies on a distinction between "proximate" and "non-proximate" matter. When Aristotle says that the body is matter for a living thing, he may be using the word "body" to refer to the matter that makes up the fully organized body, rather than the fully organized body itself. Unlike the fully organized body, this "body" remains the same thing even after death. In contrast, when he says that the body is no longer the same after its death, he is using the word "body" to refer to the fully organized body.


Aristotle says that the intellect (nous), the ability to think, has no bodily organ (in contrast with other psychological abilities, such as sense-perception and imagination).[33] Aristotle distinguishes between two types of intellect.[34] These are traditionally called the "passive intellect" and the "active (or agent) intellect".[35] He says that the "active (or agent) intellect" is not mixed with the body[36] and suggests that it can exist apart from it.[37] In his Metaphysics book Xll, he equates the active nous with the unmoved mover, of the universe, the cosmic nous, which is an idea already present in the texts of Plato.

The passive nous is like clay; it can become anything and is subject to change. The function of the active nous is to give form to the passive nous. Aristotle opposed Plato's idea that the soul carries memories of previous lives with it and attributed the faculty of memory to the passive nous, which, by the virtue of being subject to change, can die.

According to one interpretation, a person's ability to think (unlike his other psychological abilities) belongs to some incorporeal organ distinct from his body.[38] This would amount to a form of dualism.[39] However, according to some scholars, it would not be a full-fledged Cartesian dualism.[40] This interpretation creates what Robert Pasnau has called the "mind-soul problem": if the intellect belongs to an entity distinct from the body, and the soul is the form of the body, then how is the intellect part of the soul?[41]

Another interpretation rests on the distinction between the passive intellect and the agent intellect. According to this interpretation, the passive intellect is a property of the body, while the agent intellect is a substance distinct from the body.[42][43] Some proponents of this interpretation think that each person has his own agent intellect, which presumably separates from the body at death.[44][45] Others interpret the agent intellect as a single divine being, perhaps the unmoved mover, Aristotle's God.[46][47]

A third interpretation[48] relies on the theory that an individual form is capable of having properties of its own.[49] According to this interpretation, the soul is a property of the body, but the ability to think is a property of the soul itself, not of the body. If that is the case, then the soul is the body's form and yet thinking need not involve any bodily organ.[50]

Universal hylomorphism

The Neoplatonic philosopher Avicebron (a.k.a.Solomon Ibn Gabirol) proposed a Neoplatonic version of this Aristotelian concept, according to which all things, including soul and intellect, are composed of matter and form.[51]

Medieval modifications

Medieval theologians, newly exposed to Aristotle's philosophy, applied hylomorphism to Christian doctrines such as the transubstantiation of the Eucharist's bread and wine into the body and blood of Jesus. Theologians such as Duns Scotus and Thomas Aquinas developed Christian applications of hylomorphism.

Plurality vs. unity of substantial form

Many medieval theologians and philosophers followed Aristotle in seeing a living being's soul as that being's form--specifically, its substantial form. However, they disagreed about whether X's soul is X's only substantial form. Some medieval thinkers argued that X's soul is X's only substantial form, responsible for all of the features of X's body.[52] In contrast, other medieval thinkers argued that a living being contains at least two substantial forms--(1) the shape and structure of its body, and (2) its soul, which makes its body alive.[53]

Thomistic hylomorphism

Thomas Aquinas claimed that X's soul was X's only substantial form, although X also had numerous accidental forms that accounted for X's nonessential features.[54] Aquinas defined a substantial form as that which makes X's matter constitute X, which in the case of a human being is rational capacity.[55] He attributed all other features of a human being to accidental forms.[56] However, Aquinas did not claim that the soul was identical to the person.[57] He held that a proper human being is a composite of form and matter, specifically prime matter. Form and matter taken separately may retain some of the attributes of a human being but are nonetheless not identical to that person.[58] So a dead body is not actually or potentially a human being.[59]

Eleonore Stump describes Aquinas' theory of the soul in terms of "configuration". The body is matter that is "configured", i.e. structured, while the soul is a "configured configurer". In other words, the soul is itself a configured thing, but it also configures the body.[60] A dead body is merely matter that was once configured by the soul. It does not possess the configuring capacity of a human being.

Aquinas believed that rational capacity was a property of the soul alone, not of any bodily organ.[61] However, he did believe that the brain had some basic cognitive function.[62] Aquinas' attribution of rational capacity to the soul allowed him to claim that disembodied souls could retain their rational capacity, although he was adamant that such a state was unnatural.[63]

Teleology and ethics

Aristotle holds a teleological worldview: he sees the universe as inherently purposeful. Basically, Aristotle claims that potentiality exists for the sake of actuality.[64] Thus, matter exists for the sake of receiving its form,[65] and an organism has sight for the sake of seeing.[66] Now, each thing has certain potentialities as a result of its form. Because of its form, a snake has the potential to slither; we can say that the snake ought to slither. The more a thing achieves its potential, the more it succeeds in achieving its purpose.

Aristotle bases his ethical theory on this teleological worldview. Because of his form, a human being has certain abilities. Hence, his purpose in life is to exercise those abilities as well and as fully as possible.[67] Now, the most characteristic human ability, which is not included in the form of any other organism, is the ability to think.[68] Therefore, the best human life is a life lived rationally.[69]

Modern physics

The idea of hylomorphism can be said to have been reintroduced to the world when Werner Heisenberg invented his duplex world of quantum mechanics. In his 1958 text Physics and Philosophy, Heisenberg states:

In the experiments about atomic events we have to do with things and facts, with phenomena that are just as real as any phenomena in daily life. But atoms and the elementary particles themselves are not as real; they form a world of potentialities or possibilities rather than one of things or facts ... The probability wave ... mean[s] tendency for something. It's a quantitative version of the old concept of potentia from Aristotle's philosophy. It introduces something standing in the middle between the idea of an event and the actual event, a strange kind of physical reality just in the middle between possibility and reality.[70]

A hylomorphic interpretation of Bohmian mechanics has been suggested, in which the cosmos is a single substance that is composed of both material particles and a substantial form.[71]

See also


  1. ^ Physics 194b23-24
  2. ^ Physics 195a16
  3. ^ Physics 194b9
  4. ^ Robinson 18-19
  5. ^ Physics 195a6-8
  6. ^ Metaphysics 1045a26-29
  7. ^ On the Soul 424a19
  8. ^ On the Soul 418a11-12
  9. ^ Categories 2a12-14
  10. ^ Cross 34
  11. ^ Kenny 24
  12. ^ Cross 94
  13. ^ Kenny 24
  14. ^ Leftow 136-37
  15. ^ Kenny 25
  16. ^ On the Soul 413a20-21
  17. ^ On the Soul 414a3-9
  18. ^ On the Soul 412a20, 414a15-18
  19. ^ On the Soul 412b5-7, 413a1-3, 414a15-18
  20. ^ 412b5-6
  21. ^ On the Soul 407b20-24, 414a22-24
  22. ^ Robinson 45-47
  23. ^ Robinson 46
  24. ^ Robinson 46
  25. ^ Robinson 47
  26. ^ Vella 92
  27. ^ Shields, Aristotle 290-93
  28. ^ Shields, Aristotle 291
  29. ^ On the Soul 412b19-24
  30. ^ 412b15
  31. ^ Shields, Aristotle 293
  32. ^ Shields, "A Fundamental Problem"
  33. ^ On the Soul 429a26-27
  34. ^ On the Soul 15-25
  35. ^ Robinson 50
  36. ^ On the Soul 429a24-25
  37. ^ On the Soul 413b24-26, 429b6
  38. ^ Caston, "Aristotle's Psychology" 337
  39. ^ Caston, "Aristotle's Psychology" 337
  40. ^ Shields, "Some Recent Approaches" 165
  41. ^ Pasnau 160
  42. ^ McEvilley 534
  43. ^ Vella 110
  44. ^ Caston, "Aristotle's Two Intellects" 207
  45. ^ Vella 110
  46. ^ Caston, "Aristotle's Psychology" 339
  47. ^ Caston, "Aristotle's Two Intellects" 199
  48. ^ Shields, "Soul as Subject"
  49. ^ Shields, "Soul as Subject" 142
  50. ^ Shields, "Soul as Subject" 145
  51. ^ Pessin, Sarah (April 18, 2014). "Solomon Ibn Gabirol [Avicebron]". In Zalta, Edward N. (ed.). The Stanford Encyclopedia of Philosophy (Summer 2014 ed.). Retrieved 2015.
  52. ^ Kenny 26
  53. ^ Cross 70
  54. ^ Stump, "Resurrection, Reassembly, and Reconstitution: Aquinas on the Soul" 161
  55. ^ Leftow, "Soul, Mind, and Brain" 397
  56. ^ Stump, "Resurrection, Reassembly, and Reconstitution: Aquinas on the Soul" 165
  57. ^ Eberl 340
  58. ^ Eberl 341
  59. ^ Stump, "Resurrection, Reassembly, and Reconstitution: Aquinas on the Soul" 161
  60. ^ Stump, "Non-Cartesian Substance Dualism and Materialism without Reductionism" 514
  61. ^ Stump,"Non-Cartesian Substance Dualism and Materialism without Reductionism" 512
  62. ^ Stump, "Non-Cartesian Substance Dualism and Materialism without Reductionism" 512
  63. ^ Stump, "Non-Cartesian Substance Dualism and Materialism without Reductionism" 519
  64. ^ Irwin 237
  65. ^ Metaphysics 1050a15
  66. ^ Irwin 237
  67. ^ Nichomachean Ethics 1098a16-18
  68. ^ Nichomachean Ethics 1098a1-5
  69. ^ Nichomachean Ethics 1098a7-8
  70. ^ Heisenberg, W. (1958). Physics and Philosophy. London: Allen and Unwin. p. 41.
  71. ^ Simpson, W.M.R (2021). Cosmic Hylomorphism: a powerist ontology of quantum mechanics. European Journal for Philosophy of Science. 11. doi:10.1007/s13194-020-00342-5.


  • Aristotle.
    • Metaphysics
    • Nichomachean Ethics
    • On the Soul.
    • Physics
  • Caston, Victor.
    • "Aristotle's Psychology". A Companion to Ancient Philosophy. Ed. Mary Gill and Pierre Pellegrin. Hoboken: Wiley-Blackwell, 2006. 316-46.
    • "Aristotle's Two Intellects: A Modest Proposal". Phronesis 44.3 (1999): 199-227.
  • Cross, Richard. The Physics of Duns Scotus. Oxford: Oxford UP, 1998.
  • Eberl, Jason T. "Aquinas on the Nature of Human Beings." The Review of Metaphysics 58.2 (November 2004): 333-65.
  • Gilson, Etienne. The Philosophy of St. Bonaventure. Trans. F. J. Sheed. NY: Sheed & Ward, 1938.
  • Irwin, Terence. Aristotle's First Principles. Oxford: Oxford UP, 1990.
  • Keck, David. Angels & Angelology in the Middle Ages. NY: Oxford UP, 1998.
  • Kenny, Anthony. Aquinas on Mind. London: Routledge, 1993.
  • Leftow, Brian.
    • "Souls Dipped in Dust." Soul, Body, and Survival: Essays on the Metaphysics of Human Persons. Ed. Kevin Corcoran. NY: Cornell UP, 2001. 120-38.
    • "Soul, Mind, and Brain." The Waning of Materialism. Ed. Robert C. Koons and George Bealer. Oxford: Oxford UP, 2010. 395-417.
  • McEvilley, Thomas. The Shape of Ancient Thought. NY: Allworth, 2002.
  • Mendell, Henry. "Aristotle and Mathematics". Stanford Encyclopedia of Philosophy. 26 March 2004. Stanford University. 2 July 2009 <http://plato.stanford.edu/entries/aristotle-mathematics/>.
  • Normore, Calvin. "The Matter of Thought". Representation and Objects of Thought in Medieval Philosophy. Ed. Henrik Lagerlund. Hampshire: Ashgate, 2007. 117-133.
  • Pasnau, Robert. Thomas Aquinas on Human Nature. Cambridge: Cambridge UP, 2001.
  • Robinson, Timothy. Aristotle in Outline. Indianapolis: Hackett, 1995.
  • Simondon, Gilbert (2003). L'Individuation à la lumière des notions de forme et d'information [1958]. Paris: Jérôme Millon.
  • Shields, Christopher.
    • "A Fundamental Problem about Hylomorphism". Stanford Encyclopedia of Philosophy. Stanford University. 29 June 2009 <http://plato.stanford.edu/entries/aristotle-psychology/suppl1.html>.
    • Aristotle. London: Routledge, 2007.
    • "Some Recent Approaches to Aristotle's De Anima". De Anima: Books II and III (With Passages From Book I). Trans. W.D. Hamlyn. Oxford: Clarendon, 1993. 157-81.
    • "Soul as Subject in Aristotle's De Anima". Classical Quarterly 38.1 (1988): 140-49.
  • Stump, Eleanore.
    • "Non-Cartesian Substance Dualism and Materialism without Reductionism." Faith and Philosophy 12.4 (October 1995): 505-31.
    • "Resurrection, Reassembly, and Reconstitution: Aquinas on the Soul." Die Menschliche Seele: Brauchen Wir Den Dualismus. Ed. B. Niederbacher and E. Runggaldier. Frankfurt, 2006. 151-72.
  • Vella, John. Aristotle: A Guide for the Perplexed. NY: Continuum, 2008.

External links

  This article uses material from the Wikipedia page available here. It is released under the Creative Commons Attribution-Share-Alike License 3.0.



Music Scenes