  All basic syllogisms consist of three categorical sentences, in which the two premises share exactly one term, called the middle term, and the conclusion contains the other two terms, sometimes called the extremes. Based on the position of the middle term, Aristotle classified all possible premise combinations into three figures (schêmata): the first figure has the middle term (B) as subject in the first premise and predicated in the second; the second figure has it predicated in both premises, the third has it as subject in both premises: