1001Philosophers

Avicenna vs Thomas Aquinas

Avicenna's philosophy reached the Latin world before Aristotle's full corpus and shaped Aquinas's own framework decisively. Aquinas adopted, modified, and ultimately rejected key elements of Avicenna's metaphysics.

At a glance

AvicennaThomas Aquinas
Dates980 – 10371225 – 1274
NationalityPersianItalian
EraMedievalMedieval
Movements Medieval Philosophy, Islamic Philosophy Medieval Philosophy, Scholasticism, Christian Philosophy
Profile Avicenna → Thomas Aquinas →

Where they agree

Both held that the existence of God can be demonstrated by natural reason, both took the distinction between essence and existence as central to metaphysics, and both held that the soul is immortal and individual. Aquinas's philosophy of essence and existence is in dialogue with Avicenna's throughout.

Where they disagree

Avicenna held that essences are constituted prior to and independently of their existence, and that existence is an accident added to essence in created beings. Aquinas held that essence and existence are really distinct in creatures but not as substance and accident; existence is the actuality of the essence rather than an addition to it. Avicenna's necessary emanation cosmology, on which the world flows from God by necessity, was rejected by Aquinas in favor of free creation. These metaphysical disagreements have major implications for how each thinks about contingency, causation, and creation.

Representative quotes

Avicenna

  • “I prefer a short life with width to a narrow one with length.”

    As quoted in Avicenna (Ibn Sina): Muslim Physician And Philosopher of the Eleventh Century (2006), by Aisha Khan p. 85, which cites Genius of Arab Civilizations by M.A. Martin.

  • “On Medicine, ( c . 1020)”

    The knowledge of anything, since all things have causes , is not acquired or complete unless it is known by its causes. Therefore in medicine we ought to know the causes of sickness and health. And because health and sickness and their causes are sometimes manifest, and sometimes hidden and not to be comprehended except by the study of symptoms, we must also study the symptoms of health and diseas

  • “Those who deny the first principle should be flogged or burned until they admit that it is not the same thing to be burned and not burned, or whipped and not whipped.”

    Metaphysics , Book I

Thomas Aquinas

  • “The highest manifestation of life consists in this: that a being governs its own actions.”

    Vita enim in hoc maxime manifestatur quod aliquid movet se ipsum; quod autem non potest moveri nisi ab alio, quasi mortuum esse videtur.

  • “Three things are necessary for the salvation of man: to know what he ought to believe; to know what he ought to desire; and to know what he ought to do.”

    Tria sunt homini necessaria ad salutem: scilicit scientia credendorum, scientia desiderandorum, et scientia operandorum.

  • “Pange, lingua, gloriosi Corporis mysterium Sanguinisque pretiosi, Quem in mundi pretium Fructus ventris generosi Rex effudit gentium.”

    Sing, my tongue, the Savior's glory, Of His Flesh the mystery sing; Of the Blood, all price exceeding, Shed by our immortal King. | Pange, Lingua (hymn for Vespers on the Feast of Corpus Christi), stanza 1

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