René Descartes used doubt as a way to explore his ideas about knowledge. This approach is part of his rationalism, which focuses on using reason to find truth. His method is called Cartesian Doubt. It is a careful process where you question everything you believe in to find a strong base for what you know.

Central to this method is Descartes’ famous statement: “I think, therefore I am.” This means that the very act of thinking proves that he exists. He figured this out after deciding that he could doubt almost everything else around him. Even though he might not trust what his senses tell him about the world, he can’t ignore that he is thinking. This makes his thought process the first thing he knows for sure, even in an uncertain world.

By using doubt, Descartes challenges what people commonly believe. He wanted to break down ideas that could lead to confusion. His goal was to rebuild his system of knowledge, creating clear and certain ideas that everyone could trust. This method was more than just a way to criticize existing beliefs; it was a way to build a solid foundation for philosophy.

Descartes also introduced the idea of an evil demon. This is a fictional being that might trick our minds. By imagining such a creature, he showed that we should even question our strongest beliefs. This highlights the limits of what we can see and feel, which makes it clear why we need a careful way to seek knowledge.

His approach has important effects on science, logic, and math, where many ideas go untested. By insisting on thoroughly checking our beliefs, Descartes encouraged a more systematic way to discover knowledge. He showed that doubt, when used wisely, can help us find the truth.

In the end, Descartes’ method of doubt not only questions current beliefs but also paves the way for new ideas in philosophy. This marked a new chapter in Western thought, pushing people to think more deeply and explore new questions.