Petrus Thomae, Quaestiones de transcendentibus, q. 10 (W f. 27va-b)
2o sic: nichil est univocam substantie et accidenti, ergo intellectus viatoris non potest habere conceptum quidditativum de substantia. Consequentia est falsum,ergo antecedens. Falsitas consequentis patet. Probatio consequentie: substantia non immutat immediate intellectum nostrum ad intellectum sui, set tantum accidens sensibile; cuius ratio est quia quidquid presens immutat intellectum illius absentia potest naturaliter cognosci ab intellectu; set absentia substantie non potest naturaliter cognosci ab intellectu viatoris; ergo ipsa substantia presens non immutat intellectum viatoris.
Maior patet: visus enim est absentie lucis perceptivus ex 2 De anima et ideo immutari potest a luce presente. Minor probatur: nam absentia substantie panis in hostia consecrata non potest naturaliter cognosci ab intellectu viatoris.
Ex hoc probo consequentiam intentam sic: nullus conceptus quidditativus substantie potest haberi per immutationem accidentis sensibilis nisi ille possit abstrahi a conceptu accidentis; set si nullus conceptus est univocus substantie et accidenti, non potest ab ipsis aliquis conceptus abstrahi; ergo si nullus conceptus est univocus substantie et accidenti per immutationem factam ab accidente, nullus conceptus quidditativus substantie potest haberi ab intellectu nostro.
Maior patet: nisi enim aliquis conceptus substantie posset abstrahi ab accidente numquam accidens immutaret intellectum ad conceptum substantie. Ratio tamen predicta requireret prolixiorem tractatum.
Second: nothing is univocal to substance and accident, therefore the intellect of a wayfarer cannot have a quidditative concept of substance. The consequent is false, therefore so is the antecedent. The falsity of the consequence is clear. Proof of the consequence: substance does not immediately change our intellect for understanding itself, but only sensible accidents. The reason of this is that whatever present changes the intellect, the absence of it can naturally be known by the intellect; but the absence of substance cannot be naturally known by the intellect of a wayfarer; therefore substance itself when it is present does not change the intellect of a wayfarer.
The major is clear: for sight is perceptive of the absence of light from II De anima and therefore it can be changed by present light. The minor is proved: for the absence of the substance of the bread in a consecrated host cannot be naturally known by the intellect of a wayfarer.
From this I prove the intended consequence thus: no quidditative concept of substance can be had through the change of a sensible accident unless that can be abstracted from the concept of an accident; but if no concept is univocal to substance and accident, a concept cannot be abstracted from them; therefore is no concept is univocal to substance and accident by the change made by an accident, no quidditative concept of substance can be had by our intellect.
The major is clear: for unless some concept of substance can be abstracted from an accident, an accident will never change the intellect to the concept of substance. The aforesaid argument requires a more prolix treatise.
The obvious rejoinder here is to deny univocity between substance and accident and posit some kind of analogy in its place. Peter does mention this in a later argument in this section, but as he had spent the last three (very lengthy) questions on accepting and denying various kinds of analogy, this possibility is not on the table here.