perfect which possesses no limits, that is, only God." This concept would last out the entire 17th century. Subsequently, Immanuel Kant would describe perfection as "omnitudo realitatis" ("the omnitude of reality"). Thus perfection, which during the Middle Ages could be a property of any individual being, in 17th-century philosophy became as well, and indeed preeminently, a property of God. Leibniz's pupil and successor, Christian Wolff, took up this concept of perfection — but with a difference. Wolff ascribed perfection not to being as a whole, but once again to its individual constituents. He gave, as examples, an eye that sees faultlessly, and a watch that runs faultlessly. He also distinguished variants — perfectio simplex and composita, primaria and secundaria — and differentiated the magnitude of perfection (magnitudo perfectionis). Wolff's pupil, Alexander Gottlieb Baumgarten, derived perfection from rules, but anticipated their collisions (regularum collisio) leading to exceptions (exceptio) and limiting the perfection of things. Baumgarten distinguished perfection simplex and composita, interna and externa, transcendentalis and accidentalis; and, positing so broad a construction, he arrived at the conclusion that "everything is perfect". In short, Wolff and his pupils had returned to the ontological concept of perfection that the Scholastics had used. The theological concept of perfection had lived only from Descartes to Leibniz, in the 17th century. Thanks to Wolff's school, the concept of perfection lasted in Germany through the 18th century. In other western countries, however, especially France and Britain, in that century the concept of perfection was already in decline. It was ignored by the French Grande Encyclopédie. The history of the concept of perfection had undergone great evolutions — from "Nothing in the world is perfect", to "Everything is perfect"; and from "Perfection is not an attribute of God", to "Perfection is an attribute of God." With Christian Wolff's school, every thing had become perfect. This was a singular moment in the history of the ontological concept of perfection; and soon thereafter, that history came to an end. Many concepts The foregoing discussion shows that the term "perfection" has been used to designate a variety of concepts: The word "perfection" has a special meaning in mathematics, where it gives a proper name to certain numbers that demonstrate uncommon properties. In physics and chemistry, "perfection" designates a model — a conceptual construct for bodies that in reality do not precisely correspond to the model. Elsewhere the term "perfection" is used