a. and sb. [ad. late L. subcontrārius, as a term of logic transl. late Gr. ὑπεναντίος: see SUB- 19 and CONTRARY a. Cf. OF. subcontraire, F. sous-contraire.]
A. adj. 1. Somewhat or partially contrary.
1603. Holland, Plutarch’s Mor., 1038. The other [number] which surmounteth, and is surmounted by the same part of their extremities, is named Hypenantia, that is to say, subcontrary.
1697. J. Sergeant, Solid Philos., 314. Finding his Discourse in other Places Sub-contrary to what I took to be his Thoughts.
1897. Blackmore, Dariel, xxix. A conclusion not directly counter, but sub-contrary … to the view which her husband had ventured to form.
2. Logic. a. Applied to particular propositions (or the relation of opposition between them) agreeing in quantity but differing in quality.
1656. trans. Hobbes’ Elem. Philos., I. iii. 31. Subcontrary, are Particular Propositions of different Quality; as Some Man is learned, Some Man is not learned.
1826. Whately, Logic (1827), Index 347. Subcontrary opposition—is between two particulars, the affirmative and the negative.
1870. Jevons, Elem. Logic, ix. 78. Of subcontrary propositions, one only can be false, and both may be true.
b. ‘Applied to the relation between two attributes which co-exist in the same substance, yet in such a way that the more there is of one, the less there is of the other’ (Webster, 1864).
3. Geom. a. Applied to the relative position of two similar triangles having a common angle at the vertex and their bases not parallel, so that the basal angles are equal but on contrary sides. Also in a generalized sense (see quot. 1842).
1704. J. Harris, Lex. Techn., I. Subcontrary Position, (in Geometry).
1842. Penny Cycl., XXIII. 185/1. When a figure or solid is symmetrical, so that equal lines or polygons can be drawn on two different sides, those equal lines or polygons may be called subcontrary.
b. Applied to any circular section of a quadric cone in relation to the base or to another circular section not parallel to it.
1706. W. Jones, Syn. Palmar. Matheseos, 254. If cut Parallel, or Subcontrary to the Base, the Section will be a Circle.
1842. Penny Cycl., XXIII. 185/1. The generating circle ABCD has a subcontrary circle EBFD, made by taking the line EF subcontrary to AC.
1877. Encycl. Brit., VI. 283/1. If a cone be cut by a plane which does not pass through the vertex, and which is neither parallel to the base nor to the plane of a subcontrary section.
B. sb. 1. Logic. A subcontrary proposition.
1697. trans. Burgersdicius his Logic, I. xxxiii. Subcontraries are, some man is just, some man is not just…. Contraries, the negation added or taken away, contradict subcontraries.
1725. Watts, Logic, II. ii. § 3. If two particular propositions differ in quality, they are subcontraries.
1826. [see SUBALTERN sb. 3].
1864. Bowen, Logic, vi. 164. Sub-Contraries can be called ‘opposites’ only in a qualified and technical sense.
2. Geom. A subcontrary section of a cone.
1842. Penny Cycl., XXIII. 185/1. In a right cone every section has its subcontrary, except only the circle which generates the cone, and its parallels.
Hence Subcontrarily adv. (see quot.).
1728. Chambers, Cycl., s.v. Subcontrary, If the scalenous Cone BVD be so cut by the Plane CA, as that the Angle at C = D; the Cone is then said to be cut Subcontrarily to its Base BA.
