Diversity of discourse in Scripture

Averroes (d. 1198) explains why Scripture addresses its adherents in different ways in the Fasl al-Maqal, II.11-12, 15 (ed. Hourani, Leiden: 1959, emphasis mine):

.والسبب في ورود الشرع فيه الظاهر والباطن هو اختلاف فطر الناس و تباين قرائحهم في التصديف

And tasdiq, he clarifies there, is either burhani (demonstrative), jadali (dialectical), or khitabi (rhetorical).

Two senses of ‘ilm

Shams al-Din Isfahani (d. 1348), Tasdid al-Qawa’id fi’l-sharh al-Tajrid al-‘Aqa’id (Kuwait: 2012), 772:

Know that knowledge (al- ͑ilm) is [1] sometimes applied and by it is meant the occurrence of the form of a thing in the intellect. It is divided [1.1] into bare conceptualization (taṣawwur muṭlaq) – like our conception ‘the sun’, and ‘the moon, and ‘the intellect’ – and [1.2] into conceptualization with assent (taṣdīq) – like knowing that the world is temporally originated (muḥdath). Assent is a judgment, by negation or affirmation, between two things. And [2] other times [knowledge] is applied and by it is meant certainty (al-yaqīn), and is [as such] a division of assent because it is an assent qualified by jazm, thubāt, and muṭābaqa. [As such] it is not divided into conceptualization and assent that is firmly convinced (jāzim), corresponds (muṭābiq), and justified (thābit); for a thing is not divided into itself and into something different from itself.

Poetic syllogizing

There’s a certain kind of qiyas, the shaykh states in the mantiq of the Najat, 2.1-3, 9 (ed. Danishpazuh, Tehran: 1985), that

 .(…) لا يوقع تصديقاً البته و لكن تخييلا يرغب النفس في شئ أو ينفرها أو يقززها أو يبسطها أو يقبضها

That’s the poetic syllogism; it grants no tasdiq proper, only affective states. Most of tasawwuf amounts to poetic syllogizing.