1. The logical relationship between a universal affirmative proposition (the superalternate) and a particular affirmative proposition (the subalternate) with the same terms, or between a universal negative proposition (the superalternate) and a particular negative proposition (the subalternate) with the same terms. If the superalternate is true, the subalternate must be true. If the superalternate is false, the truth value of the subalternate is unknown. If the subalternate is true, the truth value of the superalternate is unknown. If the subalternate is false, the superalternate must be false. The first proposition that follows is an example of a superalternate, and the second proposition is its subalternate: “All men are mortal”; “Some men are mortal.” 

2. A term used to describe the relationship between two different sciences and the way in which they share subjects and principles.  Classically, the notion of scientific subalteration was applied to certain mixed sciences (scientiae mediae) like astronomy and optics and played a very important role in the development of classical mechanics as a mixed science using mathematical methodology and abstraction in the service of physical demonstration.  In theology, the notion of subalternation came to be used by some, including Thomas Aquinas, to refer to the nature of theological science as deriving from the knowledge possessed by God and the blessed.  In the broadest sense, such subalternation of sciences can refer to the superiority of one science over others.  Thus, physics is loosely said to be “subalternate” to metaphysics.