Introduction
From the perspective of medieval philosophers, "perfection" is one of the most important elements defining beauty [Tatarkiewicz, 1980: 136]. In the context of Islamic philosophy, Avicenna described beauty as an objective issue [Rabiei, 2011]. In medieval philosophy, Thomas Aquinas, who is indebted to Avicenna in some issues, gives a significant place to this discussion by adding the concept of perfection [Tatarkiewicz, 2005: 253].
No research was found that compared the views of Avicenna and Aquinas on the concept of perfection in defining beauty. Anwar [2003], Melbooyi [2012], Soltani [2013], Eidi [2019], Bahrami [2020b], and Jafarian [2022] in different studies to define beauty from the perspective Avicenna mentioned, but their discussion is not directly related to perfection in the definition of beauty. In addition, in separate studies, Bahrami [2019 and 2020a] and Abbasi Hosseinabadi [2016 and 2019] discussed perfection from the perspective of Avicenna. In the meantime, there is also a reference to its relationship with beauty. In the context of Aquinas's view, Amin Khandaqi [2019] directly deals with the place of the concept of perfection in the definition of beauty compared to Farabi but does not refer to Avicenna. Also, Coomaraswamy [1938], Kovach [1971], Sammon [2013], Amini [2016], Putnam [2018], Shajari et al. [2019], Pearl [2020], De Haan [2020] and O'Rourke & Gillespie [2022] have also defined beauty in Aquinas' view. After explaining the two philosophers' views, this research investigates the place of the concept of perfection in the definition of the two philosophers' beauty.
Definition of beauty according to the Avicenna viewpoint
In one of his treatises entitled "Treatise on Love", Avicenna speaks of beauty. In his view, beauty consists of three components: good order, good composition (composition), and good moderation [Avicenna, 1979]. The power of thinking in humans is the possessor of these characteristics, which, by observing the order in the compositions and verifying the moderation in this author's order, approves it in terms of compatibility with the path of his happiness [Hashem Nezhad, 2018: 52-53]. From Avicenna's point of view, crossing the boundary of tangible beauty to the realm of intangible beauty arises from comparing the two spheres of the human body and soul [Avicenna, 1986: 81]. Perceptible perceptions in the general sense and the sense of beauty in the specific sense are all confined to the field of perceptible. The soul is pleasing through these perceptions [Avicenna, 1966: 34-35]. The dignity of reason is the approbation of human desire for faces and a love for beautiful faces [Avicenna, 1979: 382-382]. According to Avicenna, "the beauty and glory of everything are that it is necessary for it" [Avicenna, 1984: 17]. When something is required and mandatory for a being, it means that if it is destroyed, that being will also be destroyed [Tabatabai, 2009: 71-78].
The concept of perfection in Avicenna's definition of beauty
Concerning the concept of perfection in the works of Avicenna, it may be said that the word "perfection" does not appear directly in any of the statements on beauty. Some researchers have presented three general concepts for the first perfection and the second perfection in the reviews of Avicenna [Wisnovsky, 2018: 230]. Generally, according to Avicenna, eight concepts of perfection are set forth:
1. Perfection according to cause and impact [Avicenna, 2007: 153].
2. Perfection on a physical or non-physical level [Avicenna, 2007: 153].
3. Perfection based on the form against the verbs derived from it [Abbasi Hosseinabadi, 2019: 151].
4. Perfection by the necessity of existence and survival [Avicenna, 1983: 21].
5. Perfection based on inherent [Abbasi Hosseinabadi, 2019: 152].
6. Perfection means face versus function [Saadat Mostafavi, 2012: 43].
7. Perfection through form and quality [Avicenna, 1983: 33].
8. Perfection through movement [Bahrami, 2019: 224].
What Avicenna talks about with the title of good order, composition, and moderation in the field of the senses is a kind of perfection or causes perfection. Also, of the eight concepts raised in Avicenna's view, three can be considered closer to "perfection" in beauty [Bahrami, 2019: 224-225].
Defining beauty from Aquinas' perspective
Of the existing writings, one can say that three definitions of beauty are the most important in Aquinas' view. "A beautiful thing makes it pleasant to be seen" [Aquinas, 2006: Ia.q5a4]. "A beauty is a perception that causes pleasure" [Aquinas, 2006: IaIIae.q27a1]. Of course, all that provokes pleasure is not the reason for its beauty; the important thing is the pleasure to see and understand [Tatarkiewicz, 2005: 380]. "Beauty is a sort of clarity and proportionality" [Aquinas, 2006: IIaIIae.q180a2]. Like this definition of beauty, both mentioned characteristics are also mentioned in other sections [Aquinas, 2006: IIaIIae.q145a2]. In addition, aquifers are only partly proportional [Aquinas, 2006: IIaIIae.q145a2] or only clearly [Aquinas, 2006: IIaIIae.q142a4] points out. In this type of definition, Aquinas commented on the view of the predecessors, and in this concept, there is no specific innovation [Tatarkiewicz, 2005: 384-385].
The notion of perfection in defining the beauty of Aquinas
In the part of his works related to the presentation of the total perfection of God, Aquinas considers the perfection of existence in an object when there is no defect or deficiency in it [Aquinas, 1905]. In his thoughts, Aquinas regards the perfection of action as the pleasure which complements the action [Aquinas, 1997]. He claims that for creatures, not everything includes perfection or good, but one can say that something is good when perfection suits it [Aquinas, 2003: 65]. Aquinas, like philosophers such as Augustine and Anselm, states, based on the concept of perfection, that absolute perfection requires the absence of any defect, combination, or need, and thus, total perfection requires complete simplicity. Based on the concept of perfection, they widened this response in an unprecedented way [Stump, 2005: 130]. Aquinas speaks of perfect alongside beauty. Beauty and perfection are two features of the created world [Aquinas, 2006: Ia.q19a10]; Although perfection in this definition is also described as the concept of appropriateness [Eco, 1988: 99] or the flawlessness of something in action [Maurer, 1983: 12]. Form, perfection, and goodness are the three elements that make the term perfection a heightened object [Aquinas, 2006: Ia.q50a1]. Finally, we can say that artworks are beautiful when complete and without defects. Absence of equal perfection ugliness [Aquinas, 1956].
Comparison of the two views
1. The two are similar in the way they deal with the concept of beauty.
2. Both philosophers came up with definitions of beauty.
3. The two of them talk about pleasure in beauty.
4. Both usually define "perfection" as completeness and lack of flaws.
5. From Avicenna's perspective, the beauty of sensations is connected with their complications. Such items are not indispensable to the existence of objects. They make something become what it deserves, but the second perfection has no place in Aquinas' definition of beauty.
6. Amongst his works, Aquinas has two kinds of divisions: primary perfection and second perfection. He says the second perfection is greater [Aquinas, 2003: 85]. Avicenna has also stated that the power of speaking in humans has these characteristics. By considering the order in the compositions and verifying the moderation in this author's order, he confirms it in terms of compatibility with the path of his happiness. It may be related to Avicenna's first and second perfections.
Conclusion
This research shows that beauty is bound up with tangible elements and summaries, according to the opinions of the two philosophers. Avicenna says perfect senses should have three aesthetic elements: good order, good composition (composition), and good moderation. Aquinas also uses the concepts of pleasure, proportion, and clarity in his definitions. These elements in the definitions of beauty may be assessed concerning the concept of second perfection.