 The distinction between conception and assertion marks the boundary between the acquisition or possession of individual concepts or notions, and the ascription of truth to statements or judgments. It provides the foundations of Avicenna’s logic (as well as those of his epistemology) and determines two distinct modes of knowledge linked on the one hand with (i) concept formation and the domain of definition (ḥadd) and description (rasm), and on the other with (ii) truth and reasoning (demonstrative and non-demonstrative syllogism (qiyās), depending on the epistemic strength of the assertions involved).