S&S Quarterly, Inc. Guilford Press The Unity of Opposites: A Dialectical Principle Author(s): V. J. McGill and W. T. Parry Source: Science & Society, Vol. 12, No. 4 (Fall, 1948), pp. 418-444 Published by: Guilford Press Stable URL: http://www.jstor.org/stable/40399913 . Accessed: 28/04/2014 18:44 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact
[email protected]. S&S Quarterly, Inc. and Guilford Press are collaborating with JSTOR to digitize, preserve and extend access to Science &Society. http://www.jstor.org This content downloaded from 128.95.104.66 on Mon, 28 Apr 2014 18:44:38 PM All use subject to JSTOR Terms and Conditions THE UNITY OF OPPOSITES: A DIALECTICAL PRINCIPLE v. j. MCGiLLand w. t. parry INTRODUCTION the unityof opposites and otherdialectical prin- ciples have sufferedvarious "refutations," and certaininter- ALTHOUGHL prêtât ions and misapplicationshave quite properlybeen laid to rest,dialectic is verymuch alive today. The Platonic-Aris- toteliantradition continues, and both the Hegelian and the Marxian dialectichave manyfollowers. The unityof opposites,which Lenin describedas the mostimportant of the dialecticalprinciples,1 states thata thingis determinedby its internaloppositions. The principlewas firstput forwardby the Milesian philosophers of the sixthcentury B.C., and by theircotemporary, Heraclitus of Ephesus.It held its own throughcenturies of philosophicalthought, though it took differentforms which were seldom clearly distin- guished.