Modern society can often be seen as a rejection of what is ‘known,’ whether that ‘known’ be true or false does not matter; and instead, it is now the acceptance of what is believed. This is the thesis for my discourse.

While this remains a claim without a citation, examples can justify it, for example: 1) people trusting viral social media posts over verified news, or 2) choosing wellness trends based on influencers rather than scientific evidence. This is a shift in the way we decipher truth(s) away from the mindset of “what is true” toward “what can I be certain of?” In this framework, the only thing that appears immune to doubt (i.e., falsehood) is not the world itself, but the act of thinking about it. Objective truth is now substituted for subjective truth (i.e., “I believe, therefore it is”), treating belief itself as a sufficient justification, regardless of whether it corresponds to a factual reality.

Naturally, this shift in thinking in the West occurred partly due to the Reformation, led by the thinking of Martin Luther. His appeal to sola scriptura and the primacy of individual conscience, most famously at the Diet of Worms (“Here I stand”), became a starting point, even if, at the time, this was not realized (Helmer, 2021). Certainty, in Luther’s view, was now located in personal conviction before the Christian God, rather than in an inherited, authoritative account of what is objectively known (Patterson, 2017). Additionally, the rise of secular politics, the growth of scientific reasoning, and the decline of religion in public life all occurred at the same time (or at least after, then in conjunction with Protestantism). As a result, many people now see modernity as closely linked to, if not identical with, secularism. From this point of view, modernity is not just linked to secularism in history. Instead, modernity is now viewed as fundamentally opposed to religious belief, leading some to conclude that reviving Christianity (or any religion as a theocracy) would require a complete rejection of modern philosophy and a reworking of thought entirely.

In The Problem of Atheism (1964), the Italian philosopher Augusto Del Noce rejected this conclusion. He argued that secularism may have followed modernity, but it need not have to. Modern philosophy, he claimed, did not begin as an attack on religion. To see why, Del Noce pointed to René Descartes (1596 – 1650), often called the founder of modern Western philosophy (Noce, 1964, p. 56). In his philosophy, Descartes started by doubting everything, including his own senses, to discover what he could be completely sure of, which was, in his view, himself as a thinking person (“Cogito, ergo sum,” Latin for “I think, therefore I am”) (Hatfield, 2024). In a nutshell, Descartes’ method of systematic doubt was intended to strip away all beliefs that could be questioned, leaving only what was absolutely certain. He used this foundation of certainty to rebuild knowledge step by step, covering both the physical world and moral truths, with God as the guarantor of knowledge (Hatfield, 2024). 

Descartes argued that God’s perfection ensures that human reason will not be deceived, thereby making his beliefs reliable, in a similar vein to Luther. While some critics accuse Descartes of circular reasoning, Descartes maintained that his proofs of God, combined with the self-evident certainty of the thinking self, provide a rational foundation for knowledge (Sorell, 2001). In other words, Descartes’ reasoning is like building a bridge: first, you firmly plant the pillars (in his view, it is the certainty of your own thinking), then you secure the structure with a trusted support (in his view, it is God), ensuring the bridge can safely carry your knowledge across the uncertainties of the world. Descartes emphasized ‘reason’ to defend Christian belief (in this case, the Holy See and Roman Catholicism), not to replace it (Doherty, 2023). The same can uniform be true of Luther: even though he maintained an emphasis on individual conscience, this was intended to guide believers toward his view of correct understanding of the New Testament, rather than to undermine religious authority. 

The later rise of rationalism (e.g., as stated above, what can I be certain of), Del Noce argued, emerged from thinkers who deliberately broke with Descartes’s religious commitments of God being a certain, rather than from Descartes’s original philosophical project (Noce, 1964, p. 315). Moreover, despite the later departures from their religious commitments, both Descartes and, in some respects, Luther are often regarded as fathers of modern secular thought, even though neither intended their ideas to promote secularism (Doherty, 2023; Sorell, 2001). However, to reduce modern Western philosophy to that standing is more rigid than fluid, and more disheartening than factual.

To understand why secularism was not inevitable, in agreement with Del Noce, it is useful to examine Descartes’ life and philosophical project in context. While Martin Luther’s earlier ideas shifted attention to individual conscience, his influence is less important for my discussion. Descartes’s careful method of doubt and certainty is simply a better way to explore the roots of modern thinking.

In the context of his life, his approach to philosophy makes sense in light of his soundings, encounters, lifestyle, and academic career. Descartes was born in La Haye, France, in 1596 and received his education at the Jesuit college of La Flèche (Smith, 2023). Initially trained in law, he later shifted his focus to philosophy and science (Smith, 2023). Following a brief period of military service, Descartes developed a strong interest in mathematics and natural philosophy (Smith, 2023). While residing primarily in the Netherlands, he authored his most significant works: Discourse on the Method (1637), Meditations on First Philosophy (1641), and Principles of Philosophy (1644) (Hatfield, 2024). These texts would lay the foundations for modern metaphysics and scientific reasoning (Smith, 2023). His contributions facilitated the transition from Aristotelian physics to a mathematically structured conception of nature and profoundly influenced later society, as I have mentioned (Smith, 2023). In his final years, Descartes moved to Sweden at the invitation of Queen Christina, where the harsh climate and demanding schedule contributed to his illness and death in 1650 at the age of fifty-three (Smith, 2023).

This brief overview of Descartes’s life provides context for his systematic approach. His structured Jesuit training must have installed both 1) rigorous and 2) logical reasoning. His engagement with mathematics and natural philosophy shaped a straightforward intellect, almost like a pencil sharpened to a fine point. Living in Europe under heavy-handed Protestant and Catholic authorities meant that questions of truth and authority were never just ‘theory’. Ideas could have real consequences for one’s social and political standing, to keep it truthful.

Seen this way, Descartes’s method of doubt is more than just theory. He was trying to justify his beliefs, much like people do today. Some argue that God does not exist, claiming that the opposition can’t prove God’s existence; Descartes did the exact opposite. Descartes reversed the burden of proof, arguing that God’s existence is required to make proof, certainty, and rational doubt itself possible. In other words, he did not infer God’s nonexistence from uncertainty; instead, he argued that the very possibility of certainty presupposes God’s existence. Both sides are similar, just with different conclusions.

Moreover, and once again, this perspective challenges the common liberal (particularly in its Enlightenment and post-Enlightenment secular forms) and modern assumption that the rise of critical reasoning and systematic doubt inevitably leads to secularism or the rejection of religion and religious practices as being fundamentally flawed and obsolete in a technical society. Many of my peers have interpreted thoughts attributed to Descartes and other early modern thinkers as the origin of a secular worldview, overlooking the fact that his philosophy was designed to secure a foundation for ‘knowledge’ that could coexist with religious belief, specifically the Christian Trinity, which can be truly difficult to justify for the Christian (Sorell, 2001). It is comical because Descartes’s own ideas were meant to justify God as the precondition of certainty, yet modern liberal atheism retains the structure of his reasoning while rejecting the very God it was designed to prove.

By focusing on certainty and rational inquiry, like many atheists and agnostics today, Descartes was not trying to weaken faith. Instead, he wanted to show that human understanding, guided by the Christian God, could be trusted even in a complicated and morally uncertain world. Today, many people separate reason from faith and equate skepticism with secularism, missing what thinkers like Descartes really meant. His work shows that careful questioning and independent thinking need not clash with religious belief. Instead, they can help both knowledge and faith grow together.