Linguistic Definition

The Arabic term mithl (likeness) implies the resemblance of something with something else. It is said hādhā mithlu hādhā (this is like this), i.e. similar to it. (Mu‘jam Maqāyīs al-Lughah, entry: m th l).

Technical Definition

It is to affirm a judgement on a particular (juz’ī) due to its establishment in another particular based on an inclusive property common to them both. Imām al-Sa‘d al-Taftazānī preferred the definition that it is to draw a comparison of one particular with another particular in a property common to them both in order to affirm the judgement established in the thing compared to (mushabbah bihi) for the thing that is compared (mushabbah) which is predicated on that property. He said that there is an oversight in the well-known definition because affirming a judgement is the result of the analogy not the reality of it. (al-Mirqāt fī ‘Ilm al-Manṭiq, p. 100; Sharḥ al-Shamsiyyah, p. 365)

Analogical argument is termed “drawing proof from the observed about the unobserved” (istidlāl al-shāhid bi l-ghā’ib) by the mutakallimūn, “comparison” (tamthīl) by the logicians and “analogy” (qiyās) by the jurists. (Sharḥ al-Shamsiyyah, p. 365; Ḥāshiyat al-‘Aṭṭār ‘alā Sharḥ Tahdhīb al-Manṭiq, p. 251).

The Components of an Analogical Argument:

1. The original case (aṣl) which is the thing with which an analogy is made
2. The new case (far‘) which is the thing analogised
3. The cause (‘illah) which is the property common to them both
4. The judgement (ḥukm) of the original case which is what extends to the new case by virtue of the cause (Fatḥ al-Raḥmān, p. 91)

The Basis of Analogy

Analogy is based on two principles. First, that a judgement in the parameter of a scriptural text is predicated on a particular property. Second, that this property is found in the new case. If these two principles are categorically established, the analogy will be decisive. Imām Fakhr al-Rāzī stated this. He added in al-Mulakhkhaṣ that the necessary conditions being found and the obstacles being negated must also be established. Al-Quṭb al-Rāzī said that acquiring knowledge via these premises is very difficult. (al-Maḥṣūl, 5:125; Nihāyat al-Sūl, p. 313; al-Mulakhkhaṣ, p. 338; Lawāmi‘ al-Asrār, p. 348).

The Method of Proving that the Common Property is a Cause for the Judgement

The logicians mention two methods. First, “alternation” (dawarān), which is that the judgement alternates with the common property in terms of both presence and absence. That is, when the property is found, the judgement is found and when the property is negated, the judgement is negated. Second, a division (taqsīm) that does not oscillate between affirmation and negation[1] and invalidating everything besides the common property as being the cause. An example of this is that the cause of the temporality of a house is either existence, or it being self-subsisting or composition. Existence and self-subsistence are not valid as causes of temporality. Thus, composition is stipulated as its cause.

According to the scholars of juristic theory, there are nine methods that prove a common property is a cause of a judgement. They termed these the “methods of identifying the cause” (masālik al-‘illah). Some of them are decisive in proving something as a cause and some of them probabilistic. These are: an explicit scriptural text (naṣṣ), an allusion (īmā’), consensus (ijmā‘), suitability (munāsabah), semblance (shabah), alternation (dawarān), restricted division (taqsīm hāṣir), generality (ṭard) and selecting the basis (tanqīḥ al-manāṭ) (Nihāyat al-Sūl, p. 319-335).

The Decisiveness of an Analogical Argument

The logicians say that an analogical argument confers probabilistic knowledge not decisive knowledge. They say that the two methods of proving that the common property is the cause of the judgement are weak. As far as “alternation” is concerned, it only confers probabilistic knowledge, because there is a need for complete induction in order to establish “alternation”; and complete induction entails we have observed the new case, which dispenses of the need to make an analogy of it with the original case. Moreover, it is possible that the “alternation” is not due to one of the two alternating items being a cause of the other, as it is possible for the common property being a part of the cause or a condition of the cause or a cause for the elimination of an obstacle.

Division only confers probabilistic knowledge because the cause may be something besides what is stated. Moreover, why is not possible that the judgement is not predicated on a cause? And even if it is conceded that the common property is the cause of the judgement in the original case, it does not necessitate its being a cause of the judgement in the new case because of the possibility that a necessary condition is absent or there is an obstacle in the new case. (Sharḥ al-Shamsiyyah, p. 365; al-Mulakhkhaṣ, p. 338-9)

The scholars of juristic theory say that some methods of establishing that a common property is the cause are decisive. With regards to logic, if it was demonstrated that the common property is a cause of the judgement through another route besides the original case, the analogical argument would transform into a demonstration (burhān) and deductive argument (qiyās). That is, it would be to deduce proof from a universal about its particulars, and so the principle of analogy is dispensed with, and mentioning the original case because of the judgement being found in it would be futile having no efficacy at all. (Sharḥ ‘Uyūn al-Ḥikmah, p. 194; Sharḥ al-Shamsiyyah, p. 366; Tasdīd al-Qawā‘id, 2:825)