On one side is Augustine, champion of Mediterranean gnosticism, faithful son of Roman authority. On the other side, Pelagius, a Celt from Britain, earthy, sensual, rebellious. Augustine's God is a transcendent spirit who stands in opposition to base matter. Pelagius's God is in and of the earth, immanent in wind, sea, sky, plants and animals. Augustine understands the world dualistically: body/soul, matter/spirit, natural/supernatural. Pelagius takes everything as one. Augustine is misogynistic; he chastises Pelagius for his associations with women and for learning from them. Pelagius is at home in his sexual identity and comfortable in the presence of women. Salvation for Augustine is by divine grace, which alone can redeem us from Adam's sin. Salvation for Pelagius is through individual responsibility, simplicity, laughter and joy; there is no Original Sin.
Here were two great defining spirits of Western spirituality, in contest for the soul of the Church. We know how the contest turned out. Augustine prevailed and the Church has ever since been primarily defined by paternalism, authoritarianism, misogyny, and contempt for fallen nature. But the Pelagian Celtic tradition survived as a kind of underground river, now and then coming to the surface -- John Scotus Erigena, Meister Eckhart, Mechtild of Magdeburg, Francis of Assisi, to mention only a few -- only to be batted back down.
If there is today in the West an inordinate tension between science and religion, it because we are heirs to an Augustinian faith tradition that stands in opposition to the very things that make science possible: a unitary view of nature, respect for the world of the senses, and a healthy skepticism for authority.