Interesting article:
Isaac Newton on the Trinity
Excerpt:
As he usually did when studying something in earnest (and what other way could Newton study?), he began a notebook, with headings of the major topics he intended to study: “The Attributes of God,” “God the Father,” God the Son,” “The Incarnation,” “Christ’s Satisfaction and Redemption.” The notes under these headings come almost entirely from Scripture. Newton approached his study of Scripture in the same methodical way he approached anything else, leaving very few stones unturned. He even collected various manuscripts of books such as Revelation, noting variant readings of significant passages.
But he was mindful that great minds had already considered these issues, and so he also studied the early church fathers. It is difficult to believe how extensively he read in the fathers. Richard Westfall writes that Newton not only “seemed to know all the works of prolific theologians such as Augustine, Athanasius, and Origen” but also was familiar with Irenaeus, Tertullian, Cyprian, Eusebius, Eutychius, Sulpitius Severus, Clement, Basil, John Chrysostom, Alexander of Alexandria, Epiphanius, Hilary, Theodoret, Gregory of Nyssa, Cyril of Alexandria, Leo I, Victorinus Afer, Rufinus, Manentius, Prudentius, and others. “There was,” Westfall says, “no single one of importance whose works he did not devour.”
At some point in his preparation for ordination, Newton began to struggle with the doctrine of the Trinity. The Trinity was a topic of deep and heated discussion during the seventeenth century, and in the Anglican Church there was considerable division over it. (Deviations from Trinitarian doctrine within the English church were rampant.) Denying the Trinity was heretical, and so Newton remained extremely cautious about his views. Over his lifetime, he seems to have changed his exact position on the doctrine of the Trinity, but it is difficult to tell. Newton never discussed publically his beliefs on the Trinity, and his notes on it were not found until after his death.
Full article here