  It has been suggested that a fourth notion—a psychologistic account of cognitive operations, and perception in particular—is a prominent goal of Gassendi's logic (Michael, 1997). While such discussion forms part of the Institutio presentation, it is by no means the main goal of the work or of Gassendi's conception of logic.  This can be seen from the thrust and length of his discussion of the first three elements, and in particular syllogistic and causal reasoning, and their attendant methodologies.