Avicenna on unity

In some places, Avicenna’s theory of unity is quite reminiscent of the Fārābian discussions, and it is not unlikely that he may have been influenced by al-Fārābī, as it is already have been noted.⁶²⁹ On the other hand, the idea that unity is an accident in everything other than God is clearly not a Fārābian doctrine.

If we look at a theological problem, namely, God’s unity, Avicenna seems to echo al-Fārābī’s views, but he differs from him as well:

He is one in all respects because He is not divisible—neither in terms of parts in actuality, [nor] in terms of parts by supposition and estimation (as with the continuous), nor in the mind in that His essence is composed of varied intellectual ideas from which an aggregate becomes united; [and] that He is one inasmuch as He does not share at all [with others] the existence that belongs to Him. He is thus, by this unity, single (fard). He is one because He is perfect in existence; nothing in Him awaits completion, this being one of the aspects of the one. The one is only in Him in a negative manner. [This is] unlike the one belonging to bodies—by reason of connection or combination—or to some other thing among [things] where the one is in it through a unity which is an existential meaning that appends itself to an essence or essences.⁶³⁰

Avicenna reiterates that God is one inasmuch as He does not share (ghayr mushārik) at all with others the existence that belongs to Him, and by this sense of unity, he is a single existent (fard).

However, Avicenna also admits that God is one only in a negative manner; that is, unity is not superadded to His Essence. His existence, being identical to His essence is that which renders it individual and one. This sense of unity resembles al-Fārābī’s unshareability criterion, but then Avicenna quickly adds that it is not a positive feature. It is still negative in the sense that the phrase “He does not share the existence with others,” is actually an apophatic statement. Still,

627 al-Fārābī, Mabādi, 46; Tr. by McGinnis-Reisman, 2007, 89.

628 See Menn, 2012, 51.

629 Janos, 2017, 102.

630 Ilāhiyyāt, 373, 8–12; tr. Marmura, 2005, 299.

147

“the existence as not shared by others’ encompasses the individuality criterion as elaborated in the Madkhal. It is not surprising at all. For al-Fārābī, this sense of unity is not accidental; it actually overlaps with the quiddity of the thing. ⁶³¹ Taken in this sense, it is not a negative feature, neither for the created existents, neither for God. Nevertheless, as we will see, it is accidental to the other existents. Therefore, it cannot be a positive, superadded feature in God’s essence because it would have entailed composition in Him.

That is, the main difference with the Second Master, is that unity is superadded to the quiddity in every existent other than God. Actually, for Avicenna one is a number, and the number is a real accident that inheres in its subject both in mente and in re.⁶³²

As we saw above, in the logical context, Avicenna elaborates on individuality in different manners. One of the formulas that he proposes recourses to unity: the quiddity in itself plus unity make up the individual. As Avicenna writes, if unity is attached to humanity in the aforementioned way, the individual human originates [from them].⁶³³ It is evident in the mental level, but it is still an open question whether this formula reflects an ontological prerequisite of becoming an individual?

Avicenna is adamant in holding that unity is an accidental notion to the quiddity. To pinpoint his realism, he adduces his famous argument on predication: the quiddity, like humanity, cannot be one by itself, because in this case, humanity would be one in number, that is, humanity would be the same in Zayd and ʽAmr.⁶³⁴ Avicenna almost consistently insists that unity is concomitant of the “thing” (shay’).⁶³⁵ In another place he links it to the substance (jawhar),⁶³⁶ and in the ʽUyūn al-ḥikma to the existent, insofar as existent, being among its essential accidents (aʽrāḍ dhātiyya).⁶³⁷ This means that for Avicenna, unity follows the quiddity just like existence;

however, it is not entirely explicit whether unity should be subordinated to the existence, or not? The passage from the ʽUyūn al-ḥikma seems to suggest this reading.⁶³⁸

Avicenna, in another passage, where he shows that unity is not a substance but a concomitant accident (lāzim), and therefore an inseparable accident, seems to understand it as an indivisible existence:

631 As opposed to „unity as truth”. Menn, 2012, 61.

632 Ilāhiyyāt, 119, 3–4. Here Avicenna speaks about numbers, and one is clearly a number. The problems arising from this tenet see Menn, 2012, 79–83.

633 Madkhal, 72, 2–3.

634 Ilāhiyyāt, 198, 3–16.

635 Ilāhiyyāt, 109, 10; Najāt, 514;

636 Ilāhiyyāt, 106, 13.

637 ʽUyūn ḥikma, 47.

638 Actually, this is how Michael E. Marmura interprets it, see Marmura, 1992, 64.

148 (...) Unity was not only indivisible but an indivisible existence so that existence is included in unity, not being a subject of it.⁶³⁹

In this sentence, unity is a specialized form of existence, but Avicenna is careful not to treat it as inhering in the substance (the subject). This implies that it is neither a constitutive nor an accidental element of existence if there is such a thing at all. Thus, it is not a concomitant accident of existence, even though it is among the essential accidents of existent qua existent, which forms the subject matter of metaphysics.⁶⁴⁰

The most famous passage that clarifies the relationship between unity and existence is the following:

Moreover, the one and the existent may be equivalent in being predicates of things, so that everything that is said to be an existent from one consideration is, from a certain consideration, correctly said to be one. [Now,]

everything has one existence.⁶⁴¹

Unity and existence mutually imply each other, but they are not the same: to be one means something else than to be existent. Therefore,

Every S[subject] which is an existent [either in mente or in re], is one Every S[subject] which is one, is existent [either in mente or in re]

For Avicenna, “one” is a modulated term⁶⁴² that may be predicated of notions that accepts indivisibility in actuality insofar as they are what they are.⁶⁴³ A thing is one if it cannot be divided insofar as it is what it is. It is interesting to note that it echoes the late-antique perception of individuals, insofar as they are labeled as ἄτομα: as Ammonius articulates it, they are indivisible, because they cannot be divided into similar species – or non-similar species, but they perish if divided.⁶⁴⁴ Thus, Socrates is not like an animal, which may be divided into human or horse.

In this sense, unity reflects one aspect of individuals – their being indivisible, and their being one among individuals.

639 Ilāhiyyāt, 108, 4–5.

640 Ilāhiyyāt, 13, 12–19.

641 Ilāhiyyāt, 303, 6–7; tr. Marmura, 2005, 236.

642 bi-l-tashkīk: that is, one may be predicated by priority and posteriority that corresponds to one accidentally, and one in itself.

643 Ilāhiyyāt, 97, 4–6.

644 Ammonius, in Isag., 63, 17–19.

149 Actually, for Avicenna one is a number, and the number is a real accident that inheres in its subject both in mente and in re.⁶⁴⁵ What concerns us most, is the one in number that covers individuals: in a very Aristotelian tone, Avicenna insists that something is one in number by continuity (bi-al-ittiṣāl), or by contiguity (bi-al-iltimās), or because of its species, or it is one in itself.⁶⁴⁶ Those things that are one because of their species are the unique instantiations of the species, as the celestial intellects and souls. The only existent that is one in itself, beyond doubt, is God. However, all the other existents are one, so that unity is superadded to the quiddity: it is accidental, but a concomitant feature.

In the Taʽlīqāt, there is a passage that links unity to the subject, and to form:

Every single subject (al-mawḍūʽāt) like a human, for example, exist as a unity, not that unity would cause its reality, but that it exists as a concept (maʽnā), and that concept is itself a unity.⁶⁴⁷

Although these passages are to be dealt with great care – it suggests that the subject, the substance human, exists as a unity. If this passage may be attributed to Avicenna, then unity, just like existence, is linked to the substantial form. Taking into account the passages above, it is a unity that means the indivisible nature of existence that it is one among the existents. In God’s case, it means indeed that He is unshareable. However, this unshareability does not depend on the existence itself; instead, it is due to unity. It is a unity that explains its unshareability. Unity, at the same time, is a coextensive term with existence, and their intensional difference means precisely this: existence means the act of existence, and unity its being one.

To sum up: unity and existence are integral features of the individual, but they mean different things: existence that it actually exists, and unity that it has an indivisible and unshareable existence. Since existence ultimately derives from God, unity should seem to be similar in this respect. Nevertheless, Avicenna, in his authentic and extant works, seems reluctant to assert such a view. The accidentality of unity sounds very Neoplatonic in tone: the Liber de Causis proposes a similar view: the Real One emanates (mufīd) unity (waḥdāniyya) to all the beings.

Avicenna, however, does not explicitly supports this idea. Unity is superadded to the quiddity in itself, which is not like all the other accidents on the one hand, and it is coextensive with

645 Ilāhiyyāt, 119, 3–4. Here Avicenna speaks about numbers, however, one is clearly a number. The problems arising from this tenet see Menn, 2012.

646 Ilāhiyyāt, 98, 1–2.

647 Taʽlīqāt, (B) 90, (M) 247 [404]. Here, I relied on Mūsawiyān’s punctuation, but in one place I preferred the Badawī reading - waḥdatan for waḥdatahu. Mūsawiyān’s reading would sound as follows: Every single subject, like the human, produces its unity, not that unity causes its reality, but it produces a concept and that concept in itself a unity.

150 existence on the other. In this reading, it is a unity that means indivisibility and unshareability, but it is not the same as existence. This latter reading is also corroborated by Avicenna’s logical formula (quiddity + unity produces the individual quiddity),⁶⁴⁸ although this latter means a mental construction. Although Avicenna does not explicitly write in his authentic works that unity, as emanating from God renders a thing individual, this is what the semantic aspect of unity just explains. Existence in itself does not mean particularity; instead, as being correlational terms with unity, it is the latter that seems to explains its distinctness.

In the following, we turn to Avicenna’s view on the particularization of existence. The key term, ʽayn – taʽayyun, has already appeared among the synonyms of the individual.