The period which many historians of science call the scientific revolution can be roughly dated as having begun in 1543, the year in which Nicolaus Copernicus published his De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) and Andreas Vesalius published his De humani corporis fabrica (On the Fabric of the Human body). As with many historical demarcations, historians of science disagree about its boundaries. Although the period is commonly dated to the 16th and 17th centuries, some see elements contributing to the revolution as early as the middle ages,Grant, Edward. The Foundations of Modern Science in the Middle Ages: Their Religious, Institutional, and Intellectual Contexts. Cambridge: Cambridge Univ. Pr., 1996. and finding its last stages--in chemistry and biology--in the 18th and 19th centuries.Herbert Butterfield, The Origins of Modern Science, 1300-1800. There is general agreement however, that the intervening period saw a fundamental transformation in scientific ideas in physics, astronomy, and biology, in institutions supporting scientific investigation, and in the more widely held picture of the universe. As a result, the scientific revolution is commonly viewed as a foundation and origin of modern science.?Scientific Revolution? MSN Encarta. 2007. MSN Encarta. 15 August 2007 http://encarta.msn.com/encyclopedia_701509067/Scientific_Revolution.html The "Continuity Thesis" is the opposing view that there was no radical discontinuity between the development of science in the Middle Ages and later developments in the Renaissance and early modern period.