René Descartes, the founder of modern philosophy, was furiously condemned by his contemporaries. Why did they fear him?

The philosopher who sowed doubt and fear. Imagine a figure who we now consider a pillar of rationality and modern thought, but who was viewed with suspicion and often accused of being manipulative, even diabolical, by his contemporaries. René Descartes, famous for his "I think, therefore I am", was not always the symbol of clarity and reason that he represents today. In the 17th century, his philosophy was seen as a threat, not only because of the ideas he proposed, but because of the profound way in which he shook the foundations of knowledge and identity. At a time when religious and intellectual authorities held a monopoly on truth, Descartes invited people to question every belief, to doubt everything they had been taught. For some, this call for "self-ignorance" appeared to be a powerful weapon, capable of stripping people of all certainty and making them vulnerable, ready to blindly rely on those who offered new assurances. Critics such as Meric Casaubon and Martin Schoock accused him of manipulating minds: according to them, Descartes led his readers to a state of despair, depriving them of their knowledge, and then offered himself as the only guide capable of restoring their confidence and stability. A sort of journey on an emotional roller coaster, in which the philosopher provoked deep crises and then dispensed comfort, creating an intellectual dependence. These accusations resonate with modern insights into psychological manipulation, similar to what we now call gaslighting. Cartesian doubt, so celebrated as a philosophical virtue, was then seen as a threat to mental and social stability. His detractors feared that this insistence on questioning everything could lead, especially the less educated, to mental confusion or even madness. Yet, precisely this abandonment of old certainties, this immersion in doubt and anguish, was for Descartes the necessary premise for rebuilding knowledge on a solid and personal basis. The religious context amplified the fears: for Protestants, the Cartesian method was too reminiscent of the control strategies attributed to the Catholic hierarchies, accused of keeping the people in ignorance. In an era marked by religious wars and mutual suspicion, Descartes' thought seemed to threaten not only the intellectual order, but also the spiritual and social order. Today, we tend to forget the emotional and traumatic dimension of the experience described in his most famous texts. The Cartesian path starts from the pain of disillusionment, from the discovery that what was believed to be true was actually false, and from the consequent need to purify the mind, even at the cost of going through moments of bewilderment and loneliness. A painful but fundamental stage for the birth of a new intellectual autonomy. This is why Descartes was feared as much as he was admired: not only did he question ideas, but he forced people to question themselves, opening the door to an inner journey as risky as it was revolutionary.