means A form of deductive reasoning where a conclusion is drawn from two premises that share a common term — classically, all A are B, all B are C, therefore all A are C.

from From Greek syllogismos, "a reckoning together" or "inference," built from syn- ("together") plus logizesthai ("to reason, to compute"), itself rooted in logos ("word, reason, account"). Aristotle gave the term its technical life in his logical works, laying out the patterns of valid inference; it traveled through Latin syllogismus into medieval scholastic logic, where generations of philosophers drilled its forms, and reached English in the late Middle Ages.