René Descartes was a philosopher who had some interesting ideas that really made people think differently about how we know things. One of his most famous sayings is "Cogito, ergo sum," which means "I think, therefore I am." This idea helps us understand some important points about knowledge.

Doubting What We See

• Empiricism is the belief that knowledge comes mainly from what we experience through our senses.
• However, Descartes didn’t trust our senses completely. He argued they can be tricked. For example, we might see illusions or have dreams that confuse us about what’s really happening.
• Because of this, he believed that instead of just accepting what our senses tell us, we should question and doubt it first.

Knowing You Exist

• In the middle of all this doubt, when Descartes says "I think, therefore I am," he means that thinking is proof that we exist.
• This self-awareness is super important in his ideas. It’s something that we can always trust, unlike our senses, which can be mistaken.

The Importance of Thinking

• Descartes flipped the idea of empiricism upside down by saying that thinking is more important than what we see.
• While empiricists believe knowledge starts with what we see and feel, Descartes claimed that real knowledge comes from ideas we already have in our minds and from reasoning.
• For him, our mind’s ability to think clearly gives us immediate certainty, which is more reliable than what we see.

Building Knowledge

• The phrase "Cogito" not only reminds us that we exist but also allows us to explore more truths about the world.
• By starting with the certainty of our own existence, Descartes encourages us to keep asking questions, leading to a deeper understanding of knowledge.

Comparing Views on Knowledge

• Empiricism focuses on observing and experiencing as the core of knowledge. But what someone sees can depend on their personal viewpoint.
• Descartes responds to this by suggesting there's a basic truth we can all agree on: if we are thinking, we exist.

In short, Descartes’ idea of "I think, therefore I am" gives us a new way to look at knowledge. It challenges the idea that we can only learn from what we sense, and instead supports a way of thinking that helps us build a stronger understanding of the world.