Text 10. The subject matter of logic, I mean, the thing which the logician investigates in respect of its concomitants in so far as it is what it is, are precisely conceptions and assents. [This is] because [the logician] investigates what conduces to conception and what the means [to conception] depends upon (for something to be universal and particular, essential and accidental, and such like); and he investigates what conduces to assent and what the means to assent depends upon, whether proximately (like something being a proposition or the converse of a proposition or the contradictory of a proposition and such like) or remotely (like something being a predicate or a subject). These are states which inhere in conceptions and assents in so far as they are what they are. So certainly its subject matter is conceptions and assents. (Tûsî  Ta‘dîl [1974b] 144.14–20)