Answer: Rene Descartes is known as one of history’s greatest thinkers. He is credited with exerting profound influence on mathematics, science, and philosophy. It could be said that his impact on the Christian faith was a ricochet: a Christian worldview deeply affected Descartes’ approach, and his approach resulted in notable contributions to Christian thought. Descartes emphasized the way in which reason and logic point toward the existence of God and objective truth. His insistence that truth can be known and understood helps bridge the gap between intellectual understanding and trusting faith. On the other hand, his trust of human intellect, his nebulous concept of “doubt,” and his thorny version of dualism are challenges that often conflict with a fully biblical worldview.

Perhaps the most valuable impact of Descartes’ philosophy is in demonstrating the inherent rationality of Christian faith. Descartes argued that, for rationality and intellect to have any meaning at all, the mind must be something “more than” matter. This touches on debates over the body-soul-spirit relationship. At the very least, Descartes’ arguments lend support to an idea known as minimal dualism, which implies that the mind and body are distinguishable but not entirely disconnected. This can be an important point in discussing Christianity with a skeptical non-believer.

Descartes’ approach to skepticism, while controversial, can strengthen the validity of one’s Christian faith. Descartes insisted on acknowledging that error was a part of human experience. The idea that some of what we think or believe might be wrong was central to his philosophy. This cautious skepticism closely aligns with the Bible’s frequent teachings on fact-checking, personal response to truth, verification, and humility (Acts 17:11; 1 John 4:1; Jeremiah 17:9; Proverbs 18:17). Rene Descartes’ faith in God serves as a prime example of how faith need not be “blind” or unscientific.

At the same time, Descartes’ thinking inspired changes in Western philosophy that have often directly challenged the Christian worldview. The introspective skepticism of Descartes has largely evolved into hardened criticism, particularly of religious faith and religion. Especially in a post-Christian framework, placing high importance on human reason can enhance the assumption that God is unnecessary. That was not Descartes’ conclusion, of course, but that is where his philosophical followers eventually landed.

As with many impactful thinkers, Descartes also inspired rebuttals to his work. Some of these are more beneficial than others. The mirror image to Descartes’ rationalism is fideism, which suggests that faith and reason are totally incompatible and that trust in God must be independent of logic and evidence. While fideism correctly recognizes that human reason is not self-sufficient to prove or disprove God, it also espouses the essence of “blind faith,” an unbiblical concept.

The impact of Rene Descartes on the Christian faith is a combination of positive and negative factors. His example and much of his work provide strong arguments for the Christian faith that ought to resonate with reason-minded skeptics or non-believers. These same points should encourage Christians to seek deeper understanding and be more confident in the truths of their faith. At the same time, Descartes’ philosophy laid the groundwork for the extreme skepticism of many modern philosophers, and some of his philosophical ideas ultimately prioritize rationalism over the Christian worldview.