Aristotle's writings were taught in the Academy in Athens until 529 CE when the Byzantine Emperor Justinian I closed down non-Christian schools of philosophy.
Aristotle's work however continued to be taught as a part of secular education. Aristotle's teachings spread through the Mediterranean and the Middle East, where some early Islamic regimes allowed rational philosophical descriptions of the natural world. Alfarabi was a major influence in all medieval philosophy and wrote many works which included attempts to reconcile the ethical and political writings of Plato and Aristotle. Later Avicenna, and later still Averroes, were Islamic philosophers who commented on Aristotle as well as writing their own philosophy in Arabic. Averroes, a European Muslim, was particularly influential in turn upon European Christian philosophers, theologians and political thinkers.
In the twelfth century, Latin translations of Aristotle's works were made, enabling the Dominican priest Albert the Great and his pupil Thomas Aquinas to synthesize Aristotle's philosophy with Christian theology. Later the medieval church scholasticism in Western Europe insisted on Thomist views and suppressed non-Aristotelian metaphysics. Aquinas' writings are full of references to Aristotle, and he wrote a commentary on Aristotle's Nicomachean Ethics. Aquinas also departed from Aristotle in certain respects. In particular, his Summa Theologica argued that Eudaimonia or human flourishing was held to be a temporary goal for this life, but perfect happiness as the ultimate goal could only be attained in the next life by the virtuous. Aquinas also added new theological virtues to Aristotle's system: faith, hope and charity. And supernatural assistance could help people to achieve virtue. Nevertheless, much of Aristotle's ethical thought remained intact in Aquinas. Aristotle's ethics continued to be highly influential for many centuries. After the Reformation, Aristotle's Nicomachean Ethics was still the main authority for the discipline of ethics at Protestant universities until the late seventeenth century, with over fifty Protestant commentaries published on the Nicomachean Ethics before 1682.
In modern times, Aristotle's writings on ethics remain among the most influential in his broad corpus, along with The Rhetoric, and The Poetics, while his scientific writings tend to be viewed as of more strictly historical interest. Modern science develops theories about the physical world based on experiments and careful observation—in particular, on the basis of exact measurements of time and distance. Aristotle, on the other hand, bases his science largely on qualitative and non-experimental observation. Accordingly, he made some inaccurate claims which have been overturned—such as the claim that objects of different mass accelerate at different rates due to gravity.
On the other hand, The Nicomachean Ethics continues to be relevant to philosophers today. In fact, virtue ethics takes its inspiration from Aristotle's approach to ethics—in particular, sharing his emphasis on character excellence, and ethical psychology. Some philosophers, in particular Bernard Williams, regard Aristotle's ethics as superior to the Utilitarian and Kantian traditions, which have come to be the dominant approaches to philosophical ethics. Aristotle's well-known function argument is less commonly accepted today, since he seems to use it in order to develop a claim about human perfection from an observation from what is distinctive about man. But the exact role of the function argument in Aristotle's ethical theory is itself a matter of dispute.