About 2 years ago, I noted Peter Leithart’s explanation of the term idios in Athanasius’ theology. Now, Leithart passes on Khaled Anatolios’ explanation of the way that Athanasius and the Council of Nicaea viewed the term homoousios. This term meant that the Son is “of the same substance” as God the Father, not a created being of a similar substance (homoiousios). To sum up Anatolios’ view, Athanasius believed that homoousios was a concept derived from the Bible that then was used to interpret the Bible, “regulating how scriptural language as a whole refers to God and Christ.” You can see the explanation in a fuller form by looking at the link. Leithart is referring to Anatolios’ recent book Retrieving Nicaea: The Development and Meaning of Trinitarian Doctrine.