[do] -- Aristotle's syllogisms
Aristotle’s Prior Analytics divides syllogisms into three basic “figures”. The variables x, y, and z represent the logical operations of universal affirmative, universal negation, particular affirmative, and particular negation. We do not care about the precise operation here. Instead, the general structure is what matters.
Figure 1
AxB
ByC
Therefore, AzC.
Figure 2
AxB
AyC
Therefore, BzC.
Figure 3
AxB
CyB
Therefore, AzC.
When discussing the second and third figures in Book I Chapters 5 and 6, Aristotle often applies logical conversions to reduce things into the first figure. He seems to think that Figure 1 syllogism are easiest to understand.
This is because Figure 1 syllogisms leverage the transitive property, a fundamental structure of human cognition. The B term acts as a “bridge” connecting A and C. The format of Figure 1 makes it simpler to process this relationship. This, in turn, makes it easier to justify the often abstruse chains of logic in Figure 2 and 3 syllogisms.