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Περί του όντος και της ουσίας
Ο Θωμάς Ακινάτης (Thomas de Aquino, 1225-1274) είναι μια κορυφαία φυσιογνωμία του Μεσαίωνα. Έχει συγγράψει μια σειρά από θεμελιώδη θεολογικά και φιλοσοφικά βιβλία, ανάμεσα στα οποία μια ιδιαίτερη θέση κατέχει το νεανικό φιλοσοφικό του πόνημα: «Περί του όντος και της ουσίας» («De ente et essentia»). Πρόκειται για ένα εγχειρίδιο μεταφυσικής, που χρησίμευε ως πανεπιστημιακό βοήθημα για τους δομινικανούς μοναχούς που σπούδαζαν στο Παρίσι. Αλλά τόση είναι η πυκνότητα και η ωριμότητα του λόγου, ώστε αυτό το μικρό έργο (oposculum) δεν έχει να ζηλέψει τίποτε από τα κατοπινά έργα του Ακινάτη.
Εισαγωγή του μεταφραστή
1. Η σχέση μεταξύ του Όντος και της Ουσίας
2. Τι είναι το Ον;
3. Τι είναι η Ουσία;
4. Τι είναι το Είναι;
5. Η αρχή ως ύλη εξατομίκευσης
6. Η παρούσα έκδοση
7. Επιλογή βοηθητικής βιβλιογραφίας
Θωμά Ακινάτη: «Περί του όντος και της ουσίας», Κείμενο - Μετάφραση - Σχόλια
Προοίμιο
Κεφάλαιο 1ο
Τι εννοείται γενικά με τις λέξεις «ουσία» και «ον»
Κεφάλαιο 2ο
Πώς συναντάται η ουσία στις σύνθετες υποστάσεις και τι περιέχει σ' αυτές η λέξη «ουσία»
Κεφάλαιο 3ο
Πώς σχετίζεται η ουσία προς την έννοια του γένους, του είδους και της ειδοποιού διαφοράς
Κεφάλαιο 4ο
Κατά ποιον τρόπο υπάρχει η ουσία μέσα στις χωριστές υποστάσεις
Κεφάλαιο 5ο
Πώς βρίσκεται η ουσία κατά διαφορετικό τρόπο μέσα στα διαφορετικά όντα
Κεφάλαιο 6ο
Πώς υπάρχει η ουσία μέσα στα συμβεβήκοντα
ΠΙΝΑΚΑΣ ΕΝΝΟΙΩΝ
Εισαγωγή του μεταφραστή
1. Η σχέση μεταξύ του Όντος και της Ουσίας
2. Τι είναι το Ον;
3. Τι είναι η Ουσία;
4. Τι είναι το Είναι;
5. Η αρχή ως ύλη εξατομίκευσης
6. Η παρούσα έκδοση
7. Επιλογή βοηθητικής βιβλιογραφίας
Θωμά Ακινάτη: «Περί του όντος και της ουσίας», Κείμενο - Μετάφραση - Σχόλια
Προοίμιο
Κεφάλαιο 1ο
Τι εννοείται γενικά με τις λέξεις «ουσία» και «ον»
Κεφάλαιο 2ο
Πώς συναντάται η ουσία στις σύνθετες υποστάσεις και τι περιέχει σ' αυτές η λέξη «ουσία»
Κεφάλαιο 3ο
Πώς σχετίζεται η ουσία προς την έννοια του γένους, του είδους και της ειδοποιού διαφοράς
Κεφάλαιο 4ο
Κατά ποιον τρόπο υπάρχει η ουσία μέσα στις χωριστές υποστάσεις
Κεφάλαιο 5ο
Πώς βρίσκεται η ουσία κατά διαφορετικό τρόπο μέσα στα διαφορετικά όντα
Κεφάλαιο 6ο
Πώς υπάρχει η ουσία μέσα στα συμβεβήκοντα
ΠΙΝΑΚΑΣ ΕΝΝΟΙΩΝ
176 pages, Paperback
First published January 1, 1256
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1467 people want to read
About the author
Thomas Aquinas
2,546 books1,135 followersPhilosophy of Saint Thomas Aquinas, a Dominican friar and theologian of Italy and the most influential thinker of the medieval period, combined doctrine of Aristotle and elements of Neoplatonism, a system that Plotinus and his successors developed and based on that of Plato, within a context of Christian thought; his works include the
Summa contra gentiles
(1259-1264) and the
Summa theologiae
or theologica (1266-1273).
Saint Albertus Magnus taught Saint Thomas Aquinas.
People ably note this priest, sometimes styled of Aquin or Aquino, as a scholastic. The Roman Catholic tradition honors him as a "doctor of the Church."
Aquinas lived at a critical juncture of western culture when the arrival of the Aristotelian corpus in Latin translation reopened the question of the relation between faith and reason, calling into question the modus vivendi that obtained for centuries. This crisis flared just as people founded universities. Thomas after early studies at Montecassino moved to the University of Naples, where he met members of the new Dominican order. At Naples too, Thomas first extended contact with the new learning. He joined the Dominican order and then went north to study with Albertus Magnus, author of a paraphrase of the Aristotelian corpus. Thomas completed his studies at the University of Paris, formed out the monastic schools on the left bank and the cathedral school at Notre Dame. In two stints as a regent master, Thomas defended the mendicant orders and of greater historical importance countered both the interpretations of Averroës of Aristotle and the Franciscan tendency to reject Greek philosophy. The result, a new modus vivendi between faith and philosophy, survived until the rise of the new physics. The Catholic Church over the centuries regularly and consistently reaffirmed the central importance of work of Thomas for understanding its teachings concerning the Christian revelation, and his close textual commentaries on Aristotle represent a cultural resource, now receiving increased recognition.
Saint Albertus Magnus taught Saint Thomas Aquinas.
People ably note this priest, sometimes styled of Aquin or Aquino, as a scholastic. The Roman Catholic tradition honors him as a "doctor of the Church."
Aquinas lived at a critical juncture of western culture when the arrival of the Aristotelian corpus in Latin translation reopened the question of the relation between faith and reason, calling into question the modus vivendi that obtained for centuries. This crisis flared just as people founded universities. Thomas after early studies at Montecassino moved to the University of Naples, where he met members of the new Dominican order. At Naples too, Thomas first extended contact with the new learning. He joined the Dominican order and then went north to study with Albertus Magnus, author of a paraphrase of the Aristotelian corpus. Thomas completed his studies at the University of Paris, formed out the monastic schools on the left bank and the cathedral school at Notre Dame. In two stints as a regent master, Thomas defended the mendicant orders and of greater historical importance countered both the interpretations of Averroës of Aristotle and the Franciscan tendency to reject Greek philosophy. The result, a new modus vivendi between faith and philosophy, survived until the rise of the new physics. The Catholic Church over the centuries regularly and consistently reaffirmed the central importance of work of Thomas for understanding its teachings concerning the Christian revelation, and his close textual commentaries on Aristotle represent a cultural resource, now receiving increased recognition.
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Displaying 1 - 30 of 81 reviews
December 26, 2025
I have read through this book numerous times, and each time I am impressed by Aquinas's clear treatment of this subject. It is a difficult subject, and reading this book requires much concentration, but the person who perseveres is greatly rewarded for the hard work required to understand this subject.
February 15, 2022
Thomas Aquinas, On Being and Essence. Trans. Armand Maurier. Toronto: Pontifical Institute of Mediaeval Studies, 1968.
It’s hard to know where to start with Thomas Aquinas. His various Summas are important, but that is a steep learning curve and also demands a good, working knowledge of secondary Thomist literature. I think this current volume might be the best place to start. It is short and focused, whereas the Summa is close to being a transcript of an oral Master's thesis. The introduction by Armand Maurier makes this volume doubly good.
The argument at its most basic: being as esse is the actuality of being, the act of existence. Think of it along more dynamic lines. Being as ens is the substance that has the actuality of being. Whatever esse an ens has, the esse structures the ens.
Citations from this book will be by chapter and section. “1.1” is chapter one, section one.
“Essence must be something common to all the natures through which different beings are placed in different generas and species” (Aquinas 1.3). Neither form nor matter is an essence. Matter cannot be an essence because it is not a principle of knowledge (2.1). It can’t be either because both are needed for the being of a substance.
Key ideas: “The genus, then, signifies indeterminately everything in the species and not the matter alone” (2.8). It is the “whole” of a thing without its “this-ness,” or specific form. A genus is proportionate to the whatness of a thing; specifies to its form; and difference to the composite nature (2.9).
Human nature isn’t the form itself or the matter itself, and if we can’t know it through the matter, how do we know it? Human nature has its being in the intellect abstracted “all individuating factors” (3.6).
On Predication
We predicate something when our intellect combines and divides things (3.8).
A form is only intelligible when it is abstracted from matter, and only something immaterial can abstract it.
Key idea: a being is either uncaused, caused by the principles of its being, or receives its being from outside itself. Therefore, everything whose being is distinct from its nature receives its being from another (4.7). Thomas suggests, though doesn’t really develop it, that one could extend this chain to the first cause, pure being.
You don’t have to agree with Thomas Aquinas. I am more of a Scotist myself when it comes to knowledge of God and the human will. But if you are unfamiliar with the arguments in this book, and you choose to criticize Thomas Aquinas, then you deserve something like what happened when Ed Feser reviewed Jeffrey Johnson’s book on Aquinas.
It’s hard to know where to start with Thomas Aquinas. His various Summas are important, but that is a steep learning curve and also demands a good, working knowledge of secondary Thomist literature. I think this current volume might be the best place to start. It is short and focused, whereas the Summa is close to being a transcript of an oral Master's thesis. The introduction by Armand Maurier makes this volume doubly good.
The argument at its most basic: being as esse is the actuality of being, the act of existence. Think of it along more dynamic lines. Being as ens is the substance that has the actuality of being. Whatever esse an ens has, the esse structures the ens.
Citations from this book will be by chapter and section. “1.1” is chapter one, section one.
“Essence must be something common to all the natures through which different beings are placed in different generas and species” (Aquinas 1.3). Neither form nor matter is an essence. Matter cannot be an essence because it is not a principle of knowledge (2.1). It can’t be either because both are needed for the being of a substance.
Key ideas: “The genus, then, signifies indeterminately everything in the species and not the matter alone” (2.8). It is the “whole” of a thing without its “this-ness,” or specific form. A genus is proportionate to the whatness of a thing; specifies to its form; and difference to the composite nature (2.9).
Human nature isn’t the form itself or the matter itself, and if we can’t know it through the matter, how do we know it? Human nature has its being in the intellect abstracted “all individuating factors” (3.6).
On Predication
We predicate something when our intellect combines and divides things (3.8).
A form is only intelligible when it is abstracted from matter, and only something immaterial can abstract it.
Key idea: a being is either uncaused, caused by the principles of its being, or receives its being from outside itself. Therefore, everything whose being is distinct from its nature receives its being from another (4.7). Thomas suggests, though doesn’t really develop it, that one could extend this chain to the first cause, pure being.
You don’t have to agree with Thomas Aquinas. I am more of a Scotist myself when it comes to knowledge of God and the human will. But if you are unfamiliar with the arguments in this book, and you choose to criticize Thomas Aquinas, then you deserve something like what happened when Ed Feser reviewed Jeffrey Johnson’s book on Aquinas.
December 29, 2022
eu amo entrar no goodreads pra marcar como lido um livro de oitenta e seis páginas (incluindo capa)
May 31, 2014
A brilliant text on the topics of being and essence. Throughout the text,one can see the influence of Aristotle(the major influence,of course),Avicenna and Boethius.
In the first part,the concepts of being and essence are defined. Then it move on to essences of simple and composite substances. The concepts of genus and species are dealt with in the next step. How essence is found in substances is discussed in the next part. The entire theory part is borrowed from Aristotle. We can see the concepts of potentiality and actuality and form and matter appearing throughout. As an independent text based on Aristotelian theories,this text does justice to the master. The only problem I felt was the constant interference of God. Whenever a definition is put forth,there is given an exception with it,reserved for God. But that can't be helped since the author is Aquinas.
The text is written in clear language and is easily comprehensible,for those with a basic knowledge of classical western philosophy.
In the first part,the concepts of being and essence are defined. Then it move on to essences of simple and composite substances. The concepts of genus and species are dealt with in the next step. How essence is found in substances is discussed in the next part. The entire theory part is borrowed from Aristotle. We can see the concepts of potentiality and actuality and form and matter appearing throughout. As an independent text based on Aristotelian theories,this text does justice to the master. The only problem I felt was the constant interference of God. Whenever a definition is put forth,there is given an exception with it,reserved for God. But that can't be helped since the author is Aquinas.
The text is written in clear language and is easily comprehensible,for those with a basic knowledge of classical western philosophy.
May 19, 2014
I didn't understand a single word...It was like i was reading a book in Chinese.
December 9, 2023
A parte del Suma Teológica, creo que esta es una de las obras cruciales de Tomás de Aquino, pues aquí explica desde la lógica y categorías aristotélicas las nociones de ente y esencia, a través del los conceptos de ser, materia, forma, naturaleza, esencia o quididad, género, especie, accidente y diferencia adaptadas a la teología. Y, con ello explica también la existencia de Dios, a quien define como la causa primera. Para ello, desarrolla la idea de que el ser, al estar compuesto de forma sustancial y materia, tiene una esencia/quididad a causa de ello. Ésta esencia en las inteligencias debe tener una existencia aparte de la forma (la forma sustancial es la esencia) y por eso Aquino sostiene que la inteligencia es forma y existencia. Pero, todo aquello que conviene a algo o es causado por su propia naturaleza (la risa en el hombre, por ejemplo), le viene de un principio exterior, así como la luz en la atmósfera es por causa del sol. Asimismo, Aquino sostiene que la existencia no puede ser causada por la propia propia forma o la quididad (esencia) de la cosa (o del ser), pues todas las cosas cuya existencia es distinta de su naturaleza, existen por causa de otra. Y por ello es que es necesario que exista una causa primera y que ésta sea causa del resto de existencias por ser ella misma únicamente existencia, pues sin ella nos iríamos al infinito de las causas precedentes. Y esa primera existencia, ese primer ente que es existencia solamente, es Dios, según Aquino.
Esta pequeño tratado, bastante complejo de leer, tiene varias disquisiciones más acerca de los conceptos y categorías sobre el ser desarrolladas por Aristóteles, en las cuales hace uso de los comentaristas aristotélicos Averroes y Avicena, y por ello hay que por lo menos tener claras las categorías y nociones que desarrolla Aristóteles en su obra Metafísica, pues si no, se corre el riesgo de no entender nada. Una vez claras esas nociones, la lectura se puede facilitar. En esta reseña he condensado prácticamente una parte o capítulo del libro, que creo que es el summum de su teoría, la cual ha trascendido durante siglos y ha sido base de la teología racionalista y en gran medida uno de los pilares fundamentales de la filosofía post-clásica. Es importante decir que Tomás de Aquino con su teología (filosófica) desarrollada a partir de Aristóteles (por lo que no recibió pocas críticas en su tiempo) fue el primer pensador cristiano católico (Doctor de la Iglesia) en unir la fe y la razón desde la filosofía y la teología, con lo que aportó enormemente al desarrollo del pensamiento occidental. Tomemos en cuenta que fue escrito en 1256 durante su estancia en París como profesor de los frailes dominicos en el convento de Saint-Jacques, por lo que este texto es una preparación para sus clases.
Esta pequeño tratado, bastante complejo de leer, tiene varias disquisiciones más acerca de los conceptos y categorías sobre el ser desarrolladas por Aristóteles, en las cuales hace uso de los comentaristas aristotélicos Averroes y Avicena, y por ello hay que por lo menos tener claras las categorías y nociones que desarrolla Aristóteles en su obra Metafísica, pues si no, se corre el riesgo de no entender nada. Una vez claras esas nociones, la lectura se puede facilitar. En esta reseña he condensado prácticamente una parte o capítulo del libro, que creo que es el summum de su teoría, la cual ha trascendido durante siglos y ha sido base de la teología racionalista y en gran medida uno de los pilares fundamentales de la filosofía post-clásica. Es importante decir que Tomás de Aquino con su teología (filosófica) desarrollada a partir de Aristóteles (por lo que no recibió pocas críticas en su tiempo) fue el primer pensador cristiano católico (Doctor de la Iglesia) en unir la fe y la razón desde la filosofía y la teología, con lo que aportó enormemente al desarrollo del pensamiento occidental. Tomemos en cuenta que fue escrito en 1256 durante su estancia en París como profesor de los frailes dominicos en el convento de Saint-Jacques, por lo que este texto es una preparación para sus clases.
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June 23, 2022Who said ontology was boring 😐. Doesn’t feel right to place stars on this book because it’s Aquinas but it was very dense, confusing, and boring (as Aquinas usually is - don’t hate me for saying that).
However, despite being dense, confusing, boring… once the concepts and stuff are explained (by a competent teacher) the beauty of existence and being is truly laid out before the reader as a veritable feast. This text may seem to be of little value in the beginning, but after more reflection/discussion (with lots of handholding from the prof) on the topic of being, there is a large payoff.
Aquinas has once again shown his genius in this text, a pity I’m not smart enough to appreciate/understand it in its entirety. Oh well.
However, despite being dense, confusing, boring… once the concepts and stuff are explained (by a competent teacher) the beauty of existence and being is truly laid out before the reader as a veritable feast. This text may seem to be of little value in the beginning, but after more reflection/discussion (with lots of handholding from the prof) on the topic of being, there is a large payoff.
Aquinas has once again shown his genius in this text, a pity I’m not smart enough to appreciate/understand it in its entirety. Oh well.
April 1, 2017
I have to admit, a large part of this was over my head. I have never been great at understanding works on ontology. First, every single time he talked about "quiddity" I thought of Quidditch.
With that said, perhaps a return to this discussion would be helpful for our current cultural climate. It seems that the accidents are being exalted over the essence when it comes to sexuality. The individuality is being exalted over the essence. In fact, towards the end, Aquinas connects these ideas with race (though he doesn't use those words).
In short, I probably needed to read this slowly and with someone else who knows philosophy better. But, it was a short challenging read.
With that said, perhaps a return to this discussion would be helpful for our current cultural climate. It seems that the accidents are being exalted over the essence when it comes to sexuality. The individuality is being exalted over the essence. In fact, towards the end, Aquinas connects these ideas with race (though he doesn't use those words).
In short, I probably needed to read this slowly and with someone else who knows philosophy better. But, it was a short challenging read.
December 16, 2015
Very short, still too hard for me. Will try again but I need something more elementary.
Update: Raising my rating after reading the translator's brief and lucid introduction.
Update: Raising my rating after reading the translator's brief and lucid introduction.
October 6, 2024
Une lecture brève mais éclairante quant aux notions essentielles de la métaphysique thomiste. Pour ce qu'il en est de Dietrich de Freiberg, la réfutation des thèses de Thomas d'Aquin m'a paru assez superficielle et sophistique et dotée d'une portée philosophique nettement moindre...
March 3, 2024
Estoy haciendo relectura del texto para un seminario de Agustín de Hipona y Tomás de Aquino. No recordaba lo árido y lo complejo que resulta seguir estas temáticas.
October 19, 2025
Dense, but even through the struggle I find this to be one my favorite approaches to a proof of God’s existence. It’s just so elegant and strangely magnificent, even though at this point in my intellectual development I know I’m only catching splinters of it. Will be returning in the future.
July 20, 2016
قطعاً زود بود خوندن اين كتاب. بايد نهايه رو بخونم و باز بيام سراغ اين.
May 9, 2022
Leitura obrigatória para todos(as) que têm interesse em metafísica, mesmo que seja para discordar do autor. O texto é curto, mas é certamente um daqueles que te fazem passar algumas horas para avançar algumas poucas páginas - não por falta de clareza, mas pela complexidade da temática.
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March 12, 2023Dici potest quia quidquid legitur legitur secundum modum legentis. Ergo hic lector carens arte latinitatis non totum intellegere potuit. Quod non mirandum est—etiam editionem anglicam cum difficultate lego. Sed qui discit non solum ad modum suum apprehendit, sed sicut docentis. Et Doctor Angelicus magister bonus.
August 23, 2022
I’m too dumb to appreciate it enough to give it 5 stars. I had to read other commentaries to affirm I was reading it correctly, and I still think there’s more to his arguments that was absorbed.
October 17, 2023
Absoluter Banger. Manche Stellen rafft man beim ersten Lesen nicht, aber hat mir super geholfen nen Einstieg in Aquin und auch Aristoteles zu finden.
April 27, 2023
This is the hardest metaphysical text I have read up to this point. Solid text if you already have a solid Thomistic\Aristotelian foundation.
October 18, 2025
Del ente y la esencia es un milagroso opúsculo de apenas 40 páginas donde Santo Tomás sienta las bases, antes de la treintena de edad, de lo que será todo su proyecto teológico posterior.
La maravillosa introducción de Eudaldo Forment (pues he leído la edición de la editorial BAC, no la de esta foto) que ocupa 250 páginas, 5 veces más que el texto al que introduce en sí, es un resumen de toda la Teología Tomista donde partiendo de cada capítulo del opúsculo explica los pilares filosóficos y teológicos que desarrollará el Aquinate el resto de su vida.
Santo Tomás es el genio que sintetizaria toda la tradición filosófica anterior, ya sea griega, árabe, judía o cristiana dando lugar a un férreo sistema filosófico que razona la totalidad de la creación: desde la materia hasta los ángeles, desde el alma humana y su psicología más fundamental hasta la vida interior divina. Con un esqueleto metafísico que continúa, expande y bautiza al de Aristóteles el Aquinate desentraña lo más íntimo de cada realidad que puebla el universo, los constituyentes esenciales de los entes materiales e inmateriales.
Del Ente y la Esencia ha conseguido enamorarme de una rama de la filosofía que consideraba imposible de entender y que no puede no estar por encima de todas las ramas del saber. La Metafísica, o la ontológica como se conoce hoy en día, y su proyecto de comprensión del Ser constituye realmente la aventura Filosofica por excelencia del ser humano. Ir más allá de la física no es hablar de espiritismo sino de aquello que subyace al propio proyecto científico moderno, a aquello sobre lo que se levanta cada intento de comprender la realidad, que subyace a cada razonamiento y que no puede ser evitado. Pues, si queremos explicar que es algo ¿Acaso podemos evitar la pregunta de qué es el Ser y el Existir?
La maravillosa introducción de Eudaldo Forment (pues he leído la edición de la editorial BAC, no la de esta foto) que ocupa 250 páginas, 5 veces más que el texto al que introduce en sí, es un resumen de toda la Teología Tomista donde partiendo de cada capítulo del opúsculo explica los pilares filosóficos y teológicos que desarrollará el Aquinate el resto de su vida.
Santo Tomás es el genio que sintetizaria toda la tradición filosófica anterior, ya sea griega, árabe, judía o cristiana dando lugar a un férreo sistema filosófico que razona la totalidad de la creación: desde la materia hasta los ángeles, desde el alma humana y su psicología más fundamental hasta la vida interior divina. Con un esqueleto metafísico que continúa, expande y bautiza al de Aristóteles el Aquinate desentraña lo más íntimo de cada realidad que puebla el universo, los constituyentes esenciales de los entes materiales e inmateriales.
Del Ente y la Esencia ha conseguido enamorarme de una rama de la filosofía que consideraba imposible de entender y que no puede no estar por encima de todas las ramas del saber. La Metafísica, o la ontológica como se conoce hoy en día, y su proyecto de comprensión del Ser constituye realmente la aventura Filosofica por excelencia del ser humano. Ir más allá de la física no es hablar de espiritismo sino de aquello que subyace al propio proyecto científico moderno, a aquello sobre lo que se levanta cada intento de comprender la realidad, que subyace a cada razonamiento y que no puede ser evitado. Pues, si queremos explicar que es algo ¿Acaso podemos evitar la pregunta de qué es el Ser y el Existir?
January 23, 2023
Before starting with the views of Thomas Aquinas that make up the philosophy of Christianity, I think it is necessary to start by briefly touching on Aristotle's philosophy of being, which he was very inspired by. Aristotle, on the subject of being, reveals that those who exist do not exist alone, that every being has a 'meaning of being', and reveals that the separation of the phenomenon of being that can be separated in thought is impossible in reality. At this point, there is a reference to the phenomenon of god-nature, which is one of the first topics of philosophy in the narrative of the totality of being through the soul-body relationship. As a result, the existence of God and nature is integrated on the basis of uniqueness.
Based on this point, Aquinas emphasizes integrity about being and essence. But he does it in the context of man and nature. At this point, he has separated from the Aristotelian philosophy and considers it in a different way by Deciphering the meaning of the existence of God among the meanings of being within the framework of Christianity. Although it Deconstructs the integrity of Aristotelian metaphysics in a philosophical sense, it has introduced an abstraction between beings (God-man-nature) in the philosophy of monotheistic religion. This content, which you will find in the book content, also symbolizes the philosophical infrastructure of medieval Europe. I didn't really like this book, which also contains a general explanation of the philosophy of monotheistic religions, because I opposed it in many parts, but it can serve as a good resource for readers interested in theology. Pleasant reading already. Live by transcending those who limit and isolate you. Amen.
Based on this point, Aquinas emphasizes integrity about being and essence. But he does it in the context of man and nature. At this point, he has separated from the Aristotelian philosophy and considers it in a different way by Deciphering the meaning of the existence of God among the meanings of being within the framework of Christianity. Although it Deconstructs the integrity of Aristotelian metaphysics in a philosophical sense, it has introduced an abstraction between beings (God-man-nature) in the philosophy of monotheistic religion. This content, which you will find in the book content, also symbolizes the philosophical infrastructure of medieval Europe. I didn't really like this book, which also contains a general explanation of the philosophy of monotheistic religions, because I opposed it in many parts, but it can serve as a good resource for readers interested in theology. Pleasant reading already. Live by transcending those who limit and isolate you. Amen.
June 7, 2024
In today's Postmodern existential world, the Be-ing of existence precedes essence, just as substance precedes the prescribed form it will take, for the mode and the pattern have been formalized and codified for hundreds and years by this time, to such a point that politics takes precedence over all thoughts of God.
December 1, 2025
A fundamental metaphysical work, for obvious reasons. Maurer’s translation is great, and comes with a great introduction and liberal notes/secondary sources.
Of special interest in here is the depth of connection between consciousness, logic, and being. I’m not sure I’ve parsed it out (or that I will anytime soon), but that’s a pretty important connection a lot of contemporary thought seems to miss, in my opinion (which, of course, is limited!)
Of special interest in here is the depth of connection between consciousness, logic, and being. I’m not sure I’ve parsed it out (or that I will anytime soon), but that’s a pretty important connection a lot of contemporary thought seems to miss, in my opinion (which, of course, is limited!)
December 16, 2025
Wow pretty good
September 17, 2024
Excellent work by Thomas Aquinas, as always! It's a bit shorter than I was expecting, and I don't agree with some of the axioms Aquinas draws from, but his logic is sound. As always, Aquinas is a joy to read!
October 27, 2025
As always, let us begin by commenting on the translation. I read the Peter King translation as part of the Hackett Aquinas: Basic Works volume, and it was a mixture of good and bad. Contextualizing, Mr. King is a contemporary researcher tied to Analytic philosophy, and as such, values clarity, precision and linguistic rigor. His translation mirrors his philosophical inclination, in which he seems to have strived for a word by word translation from the original Latin, in order to preserve to the utmost Aquinas' style and technical baggage. As a consequence, some passages are extremely, and I mean extremely convoluted, to the point of being barely discernible even after multiple reads. In a way, you're getting the most genuine Aquinas possible, however that comes at the cost of accessibility, specially to readers not familiar with Latin (my case). However, the incomprehensibility is mostly contained in the second and third chapters (out of the total six), which makes the translation bearable overall. But enough on this, let us begin in earnest.
On Being and Essence is a short philosophical treatise by the famous Saint, in which he devises the core of his metaphysical doctrine, drawing heavily from Aristotle. Its main point of focus is essence: what is it, how is it related to being and definition, and how is it connected to genus, species and differentia. Following my previous reviews from the Philosopher, I will highlight the points of interest that have arisen from my (slow!) read. Therefore, please forgive me for the non-structured presentation of the ideas.
We start by presenting what is essence (or quiddity, a new word unlocked), which is, as in Aristotle, that which makes something what it is; the nature of something, that makes it intelligible. In chapter 2, the first point of diversion between the two systems arises, namely that the form of a composite substance cannot be called its essence (and neither can only the matter). This arises as a way to fill a gap in Aristotelian doctrine, one that can be better illustrated by an example: If Socrates is a substance, what is his essence? It cannot be merely the form of “humanity,” for his matter also contributes to his being. Therefore, Aquinas establishes that the essence of a composite substance is both the matter and form, diverging from Aristotle. Another question then arises: is essence the same as substance? The answer is no: the principle of individuation (what makes the general particular) is said to be matter, but not any kind of matter. While essence is the composite of form and general matter, substance is the composite of form and signate (identified, particular) matter. As such, signate matter is an agent of individuation, maintaining the 'thisness' (tode ti) defended by Aristotle.
He then explores how genus and differentia signify the whole. I quote him:
Aquinas, shortly later, explains another interesting clarification regarding how we should view definition. Genus is not one general nature tying together species, on top of which the differentia are added up, determining it. Rather, it is an indeterminate form, by which the differentia expresses determinately. The first model is endearingly aliased as the "brick", in which genus and differentia are bricks that, added up, constitute definition. If it were the case, genus and differentia would be independent, self-contained metaphysical concepts, which would constitute a form of Platonism. In contrast, the second model can be thought of as a "lens": the genus is a nebulous concept that shows the commonness of the signified form, and the differentia is the lens that focuses it into the species that are diverse in essence.
We then investigate that forms are intelligible in actuality only by distancing themselves from matter, because corporeal matter prevents the intellect from grasping the universal (through the forms). As such, a being intelligible in actuality are the Intelligences (Unmoved movers, represented by angels), so that, since the Intelligences lack matter, their form is really the whole of its essence. Therefore, the essence of a composite substance differs from the essence of a simple substance in this regard.
However, thus comes another point of departure, in that Aquinas establishes that the Intelligences are not pure actuality. Intelligences are things that possess both form and existence, such that they have the potential to exist, and thus are not pure actuality. We can grasp the form of something that does not exist, such as a phoenix, therefore essence and existence are separate things. This classification (as pure actuality) is exclusive to the First Principle (God), it is God who gives existence to everything else, and it is God who is the only being whose nature and existence are the same. Concluding the point of departure, Intelligences have the potential to exist, and this existence comes from the only being that is existence only, God.
An interesting corollary arises, namely that there are degrees of being, which are devised from their proportions of potentiality and actuality. The more something is closer to pure actuality (God), the higher it is in this scale. As such, the soul occupies the lowest degree of intellectual substances, and prime matter the lowest degree of sensible existence. The claim on prime matter is obvious: since it is pure potentiality, it occupies the lowest degree, but what about the claim on the soul? First, the soul is a substance only in a qualified sense, since Aquinas believe that it persists and exists independently of the body after its death. Still, in order to fulfill its utmost potential soul needs the body, thus it is lowest on the scale of intellectual substances.
Summarizing the whole deal on how and where essence is found: Firstly, there is a being whose essence is the same as the very existence, namely God. Secondly, it is found in created intellectual substance, whose existence is dependent on God and is not the same as its essence, despite not having matter (essence = form). Thirdly, it is found in the composite substance, such that essence is the composite of general (undesignated) matter and form.
Chapter 6 then deals with accidents (secondary substances). They are only substances in the sense that their existence is tied to a primary substance, therefore they have an incomplete definition and only participate in the account of being secondarily through the cause of a primary substance. Thus ends the not so long, but so much complicated treatise.
It was interesting seeing the divergences between Aquinas and Aristotle, I only hoped his thought would be more easily grasped. Unfortunately, due to the translation, that wasn't possible to the degree I wanted. Nevertheless, I'm very interested to see how his new metaphysical system will play out in his further philosophy.
On Being and Essence is a short philosophical treatise by the famous Saint, in which he devises the core of his metaphysical doctrine, drawing heavily from Aristotle. Its main point of focus is essence: what is it, how is it related to being and definition, and how is it connected to genus, species and differentia. Following my previous reviews from the Philosopher, I will highlight the points of interest that have arisen from my (slow!) read. Therefore, please forgive me for the non-structured presentation of the ideas.
We start by presenting what is essence (or quiddity, a new word unlocked), which is, as in Aristotle, that which makes something what it is; the nature of something, that makes it intelligible. In chapter 2, the first point of diversion between the two systems arises, namely that the form of a composite substance cannot be called its essence (and neither can only the matter). This arises as a way to fill a gap in Aristotelian doctrine, one that can be better illustrated by an example: If Socrates is a substance, what is his essence? It cannot be merely the form of “humanity,” for his matter also contributes to his being. Therefore, Aquinas establishes that the essence of a composite substance is both the matter and form, diverging from Aristotle. Another question then arises: is essence the same as substance? The answer is no: the principle of individuation (what makes the general particular) is said to be matter, but not any kind of matter. While essence is the composite of form and general matter, substance is the composite of form and signate (identified, particular) matter. As such, signate matter is an agent of individuation, maintaining the 'thisness' (tode ti) defended by Aristotle.
He then explores how genus and differentia signify the whole. I quote him:
For the genus is not the matter, but derived from the matter as signifying the whole. Nor is differentia the form, but derived from the form as signifying the whole.This may sound a little confusing, so let's unpack. Genus and differentia are not names for metaphysical parts of substance, but rather ways of conceptually referring to the essence of the substance. Definition, composed of genus and differentia, is a conceptual expression of essence, and not a part of substance, that is what he means by signifying the whole. But what about being part of matter or form? What do logical concepts have to do with matter and form? Note, as we have said, that definition (genus + differentia) is used to conceptually refer to essence, and recall that essence is the composite of general matter and form. Therefore, genus and differentia are not matter and form, but derived from them in order to conceptually refer to the essence (whole).
Aquinas, shortly later, explains another interesting clarification regarding how we should view definition. Genus is not one general nature tying together species, on top of which the differentia are added up, determining it. Rather, it is an indeterminate form, by which the differentia expresses determinately. The first model is endearingly aliased as the "brick", in which genus and differentia are bricks that, added up, constitute definition. If it were the case, genus and differentia would be independent, self-contained metaphysical concepts, which would constitute a form of Platonism. In contrast, the second model can be thought of as a "lens": the genus is a nebulous concept that shows the commonness of the signified form, and the differentia is the lens that focuses it into the species that are diverse in essence.
We then investigate that forms are intelligible in actuality only by distancing themselves from matter, because corporeal matter prevents the intellect from grasping the universal (through the forms). As such, a being intelligible in actuality are the Intelligences (Unmoved movers, represented by angels), so that, since the Intelligences lack matter, their form is really the whole of its essence. Therefore, the essence of a composite substance differs from the essence of a simple substance in this regard.
However, thus comes another point of departure, in that Aquinas establishes that the Intelligences are not pure actuality. Intelligences are things that possess both form and existence, such that they have the potential to exist, and thus are not pure actuality. We can grasp the form of something that does not exist, such as a phoenix, therefore essence and existence are separate things. This classification (as pure actuality) is exclusive to the First Principle (God), it is God who gives existence to everything else, and it is God who is the only being whose nature and existence are the same. Concluding the point of departure, Intelligences have the potential to exist, and this existence comes from the only being that is existence only, God.
An interesting corollary arises, namely that there are degrees of being, which are devised from their proportions of potentiality and actuality. The more something is closer to pure actuality (God), the higher it is in this scale. As such, the soul occupies the lowest degree of intellectual substances, and prime matter the lowest degree of sensible existence. The claim on prime matter is obvious: since it is pure potentiality, it occupies the lowest degree, but what about the claim on the soul? First, the soul is a substance only in a qualified sense, since Aquinas believe that it persists and exists independently of the body after its death. Still, in order to fulfill its utmost potential soul needs the body, thus it is lowest on the scale of intellectual substances.
Summarizing the whole deal on how and where essence is found: Firstly, there is a being whose essence is the same as the very existence, namely God. Secondly, it is found in created intellectual substance, whose existence is dependent on God and is not the same as its essence, despite not having matter (essence = form). Thirdly, it is found in the composite substance, such that essence is the composite of general (undesignated) matter and form.
Chapter 6 then deals with accidents (secondary substances). They are only substances in the sense that their existence is tied to a primary substance, therefore they have an incomplete definition and only participate in the account of being secondarily through the cause of a primary substance. Thus ends the not so long, but so much complicated treatise.
It was interesting seeing the divergences between Aquinas and Aristotle, I only hoped his thought would be more easily grasped. Unfortunately, due to the translation, that wasn't possible to the degree I wanted. Nevertheless, I'm very interested to see how his new metaphysical system will play out in his further philosophy.
January 3, 2024
At around 10,000 words (in English) this is a relatively short introduction by Thomas Aquinas (d.1274) to medieval philosophical concepts essence and existence.
Chapter 1 distinguishes between two easily confused ideas of existence. Things can exist in reality (eg a tree ‘is’). But concepts are also predicated linguistically (eg a unicorn can be said to be 4 legged). The difference between real things and linguistic entities is a critically important starting point for philosophy.
Chapter 2 focuses on the first type of existence, exploring how ‘things’ have essences. We hear that entities like trees have an essence, which we can think of as its nature. While our experience of reality is an experience of material things, nevertheless immaterial things (like a square) can also have an essence.
Chapter 3 focuses on the second type of existence (ie linguistic). It explains how we have essences within the linguistic definitions and intentional ideas within our minds (eg unicorns).
Chapter 4 carries the discussion on to explore how the concept of ‘essence’ applies to a unique set of entities which are unlike the physical or mathematical entities in chapter 2. These are ‘separated substances’ like angels and souls, which share the reality of physical things, but the immateriality of mathematical entities.
Chapter 5 is a recapitulation of earlier discussions, comparing and contrasting how concepts of existence and essence are applied to the different kinds of entities discussed in chapters 2-4.
Chapter 6 closes the treatise by applying the ideas of essence and existence to ‘accidents’. These are (like) the properties predicated of things. A tree has an essence and an existence (chp 2) but it might also be described as ‘tall.’ The tallness of the tree has a kind of existence of its own, as tallness can be defined. But tallness cannot exist on its own, so it is an 'accident,' which can only be said to have an essence or existence in an extended sense of the words.
Overall, this is a difficult read for modern thinkers who are unfamiliar with medieval language. But it is also a relatively clear and straightforward introduction to that medieval thought world, for students who wish to understand it better . However, an important limitation of the book is that it cannot include consideration of issues raised after Aquinas' death, by critics such as Scotus.
Chapter 1 distinguishes between two easily confused ideas of existence. Things can exist in reality (eg a tree ‘is’). But concepts are also predicated linguistically (eg a unicorn can be said to be 4 legged). The difference between real things and linguistic entities is a critically important starting point for philosophy.
Chapter 2 focuses on the first type of existence, exploring how ‘things’ have essences. We hear that entities like trees have an essence, which we can think of as its nature. While our experience of reality is an experience of material things, nevertheless immaterial things (like a square) can also have an essence.
Chapter 3 focuses on the second type of existence (ie linguistic). It explains how we have essences within the linguistic definitions and intentional ideas within our minds (eg unicorns).
Chapter 4 carries the discussion on to explore how the concept of ‘essence’ applies to a unique set of entities which are unlike the physical or mathematical entities in chapter 2. These are ‘separated substances’ like angels and souls, which share the reality of physical things, but the immateriality of mathematical entities.
Chapter 5 is a recapitulation of earlier discussions, comparing and contrasting how concepts of existence and essence are applied to the different kinds of entities discussed in chapters 2-4.
Chapter 6 closes the treatise by applying the ideas of essence and existence to ‘accidents’. These are (like) the properties predicated of things. A tree has an essence and an existence (chp 2) but it might also be described as ‘tall.’ The tallness of the tree has a kind of existence of its own, as tallness can be defined. But tallness cannot exist on its own, so it is an 'accident,' which can only be said to have an essence or existence in an extended sense of the words.
Overall, this is a difficult read for modern thinkers who are unfamiliar with medieval language. But it is also a relatively clear and straightforward introduction to that medieval thought world, for students who wish to understand it better . However, an important limitation of the book is that it cannot include consideration of issues raised after Aquinas' death, by critics such as Scotus.
December 30, 2021
In this short work, Aquinas gives basic, concise definitions and explanations of his (Aristotelian) core metaphysical terms, namely essence, substance, form, being, and matter. He also gives an argument for the necessity of a first cause or God (prime mover), which he takes to be, essentially, being actualized - a being whose essence and actualization is simply being. This is, of course, very similar to Aristotle's first mover, although such a mover is not 'being' per se (but instead a pure actualization of thoughts that thinks the essence of itself and/as the eternal and supreme good). The precise likeness and difference is complex and worthy of a dissertation.
The only reason I am not giving it a 5/5 is the conceptual difficulties his account entails.
The exact relations between essence, form, quiddity, and substance (at least simple substances), for example, are very difficult if not impossible to untangle, since these concepts are so very similar. In one sense, this is not his - but Aristotle's - fault. In another sense, he should have modified his use of Aristotelian notions more critically or at least explained them with even more conceptual rigour than he admittedly already does. He did write this thesis at a young age, though, so I suppose we cannot blame him too much.
The only reason I am not giving it a 5/5 is the conceptual difficulties his account entails.
The exact relations between essence, form, quiddity, and substance (at least simple substances), for example, are very difficult if not impossible to untangle, since these concepts are so very similar. In one sense, this is not his - but Aristotle's - fault. In another sense, he should have modified his use of Aristotelian notions more critically or at least explained them with even more conceptual rigour than he admittedly already does. He did write this thesis at a young age, though, so I suppose we cannot blame him too much.
February 3, 2023
Ένα πολύ δύσκολο φιλοσοφικό βιβλίο του Θωμά Ακινάτη πάνω στην οντολογία. Μέχρι τα μισά του δεύτερου κεφαλαίο κάτι γινότανε όσον αφορά την κατανόηση του κειμένου, μετά τα πράγματα εκτραχύνθηκαν και το κείμενο έγινε πολύ δύσκολο, ιδιαίτερα στο έκτο κεφάλαιο με τα συμβεβηκότα. Όταν διαβάζεις ένα βιβλίο στο οποίο το ίδιο το φιλοσοφικό κείμενο είναι μικρότερο σε μέγεθος από τις υποσημειώσεις του αυτό και μόνο τα λέει όλα. Μόνη εξαίρεση είναι η αρκετά καλή και κατατοπιστική εισαγωγή, που όμως από μόνη της δεν σώζει την κατάσταση.
March 27, 2013
This book is a wonderful translation and commentary on a very difficult and profound pamphlet that was written by the young Aquinas. The difficult and profound pamphlet is the well-known "Esse et Essentia", and in this pamphlet Aquinas sets out to pose solid foundations for philosophy and theology. In order to avoid error one needs to ensure that their starting point is sure. As such, Aquinas sets out to explain what is meant by the words "Being" and "essence", how they are found in diverse things, and how they are related to the logical intentions. Joseph Bobik gives an indepth analysis and commentary on Aquinas's treatise, which is, essentially, one of the best textbooks that a professor could use for an advanced course in Thomistic Metaphysics.
January 24, 2009
Being were I am, I am supposed to be more in love than Thomas than what I am.
On the matter, I'm either too ignorant to be enlightened or too enlightened to be ignorant, but either way I'm too ignorant to know which.
1/2 star for Thomas's ending... "having said this we may make a proper end to this discourse. Amen."
having said this, I make an end to this review. Amen.
On the matter, I'm either too ignorant to be enlightened or too enlightened to be ignorant, but either way I'm too ignorant to know which.
1/2 star for Thomas's ending... "having said this we may make a proper end to this discourse. Amen."
having said this, I make an end to this review. Amen.
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