  Note the phrase, “since such notions or modes of signifying are not fictions.” The modi significandi could not play any causal role in determining the parts of speech, nor the corresponding modi intelligendi in determining the modi significandi, nor the modi essendi in determining the modi intelligendi, unless they all actually exist. Here the Modistae drew on the Aristotelian idea that although spoken sounds and written marks differ from language to language, “what these are in the first place signs of — affections of the soul — are the same for all; and what these affections are likenesses of — actual things — are also the same” (De interpretatione  1.16a3–9).[14]  Likewise, the ordering of modes was intended to replicate the ordering of disciplines in an Aristotelian speculative science: just as psychology, the study of moving things qua animate, is subordinate to physics, the study of things qua moving, and physics is subordinate to metaphysics, the study of things qua existing, so the principles of grammar (modi significandi) are derived from mental acts of signifying (modi intelligendi), which reflect the way things really are (modi essendi).