Square of Opposition

In the system of Aristotelian logic, the square of opposition is a diagram representing the different ways in which each of the four propositions of the system is logically related ('opposed') to each of the others. The system is also useful in the analysis of syllogistic logic, serving to identify the allowed logical conversions from one type to another.

Read more about Square Of Opposition:  Summary, The Problem of Existential Import, Modern Squares of Opposition, Logical Hexagons and Other Bi-simplexes

Famous quotes containing the words square and/or opposition:

    In old times people used to try and square the circle; now they try and devise schemes for satisfying the Irish nation.
    Samuel Butler (1835–1902)

    It is useless to check the vain dunce who has caught the mania of scribbling, whether prose or poetry, canzonets or criticisms,—let such a one go on till the disease exhausts itself. Opposition like water, thrown on burning oil, but increases the evil, because a person of weak judgment will seldom listen to reason, but become obstinate under reproof.
    Sarah Josepha Buell Hale 1788–1879, U.S. novelist, poet and women’s magazine editor. American Ladies Magazine, pp. 36-40 (December 1828)