Dialogues from Neoplatonic philosophy in the third century AD contributed the development of the concept the supernatural via Christian theology in later centuries. The term nature had existed since antiquity with Latin authors like Augustine using the word and its cognates at least 600 times in City of God. In the medieval period, "nature" had ten different meanings and "natural" had eleven different meanings. Peter Lombard, a medieval scholastic in the 12th century, asked about causes that are beyond nature, in that how there could be causes that were God's alone. He used the term praeter naturam in his writings. In the scholastic period, Thomas Aquinas classified miracles into three categories: "above nature", "beyond nature", and "against nature". In doing so, he sharpened the distinction between nature and miracles more than the early Church Fathers had done. As a result, he had created a dichotomy of sorts of the natural and supernatural. Though the phrase supra naturam was used since the 4th century AD, it was in the 1200s that Thomas Aquinas used the term "supernaturalis", however, this term had to wait until the end of the medieval period before it became more popularly used. The discussions on "nature" from the scholastic period were diverse and unsettled with some postulating that even miracles are natural and that natural magic was a natural part of the world.