I can't think of a western scientist being labeled as a christian scientist. However, if we talk about western thinkers we have Augustine of Hippo, usually known as St. Augustine, and Thomas Aquinas, know as St. Thomas Aquinas. They played a major role shaping the Church as we know, but they were also highly influential in western society and philosophy as a whole. Descartes jesuit education is constantly brought up when talking about his work, at least when comes to philosophy.