Metaphysics is one of the principal works of Aristotle and the first major work of the branch of philosophy with the same name. The principal subject is "being qua being," or being insofar as it is being. It examines what can be asserted about anything that exists just because of its existence and not because of any special qualities it has. Also covered are different kinds of causation, form and matter, the existence of mathematical objects, and a prime-mover God. The Metaphysics is considered to be one of the greatest philosophical works. Its influence on the Greeks, the Muslim philosophers, the scholastic philosophers and even writers such as Dante, was immense. It is essentially a reconciliation of Plato's theory of Forms that Aristotle acquired at the Academy in Athens, with the view of the world given by common sense and the observations of the natural sciences. According to Plato, the real nature of things is eternal and unchangeable. However, the world we observe around us is constantly and perpetually changing. Aristotle’s genius was to reconcile these two apparently contradictory views of the world. The result is a synthesis of the naturalism of empirical science, and the rationalism of Plato, that informed the Western intellectual tradition for more than a thousand years.