Did Isaac Newton Believe in God?

Newton was raised in the Church of England and remained outwardly Anglican throughout his life. He was elected a fellow of Trinity College, Cambridge — a position that, in 1667, required taking holy orders in the Anglican Church. Newton avoided this requirement through an unusual royal dispensation granted specifically to the Lucasian Professor of Mathematics — a dispensation he had lobbied for, almost certainly because he already knew his private beliefs were incompatible with ordination.

What Newton privately believed was a form of Christianity that rejected the Council of Nicaea (AD 325), at which the doctrine of the Trinity was formally established. Newton's historical research led him to conclude that Trinitarian doctrine was not present in the original scriptures but had been introduced by Athanasius and others for political reasons. In Newton's reading, Jesus was a being of a higher order than man but not co-equal with God — a view known as Arianism, after the 4th-century theologian Arius, and one that had been declared heretical since 381 AD.

Newton never published these views. He communicated them cautiously to a handful of trusted correspondents. His theological manuscripts — running to hundreds of thousands of words — were kept private and remained unpublished at his death. He understood perfectly well what public disclosure would have meant.

For Newton, the two were not in tension — they were aspects of the same inquiry. He believed that the mathematical order he found in nature was direct evidence of a designer, and that uncovering that order was a form of worship. When Leibniz criticised Newton's theory of gravity on the grounds that action at a distance was philosophically incoherent — how could one object affect another with nothing between them? — Newton's response was essentially theological: God maintains it. Gravity works because God makes it work.

This is sometimes read as a gap-filling move — invoking God where physics ran out. Newton probably saw it differently. For him, the universe required active divine maintenance because a universe running purely on mechanical principles, without ongoing divine involvement, would be the universe of the materialists — the atheists. Newton was not an atheist. He was, if anything, more intensely focused on God's presence in nature than most of his contemporaries.

His Opticks ends with a set of 'Queries' — open questions about the nature of light and matter — that shade, by the final pages, into natural theology. Newton's scientific writing is full of language that assumes a creator. This was not rhetorical decoration. He meant it.