Usually we say an idea or belief in our mind is true if it corresponds with what the real world outside our mind is like. In other words, whether an idea is true depends on what the real world outside...

Usually we say an idea or belief in our mind is true if it corresponds with what the real world outside our mind is like. In other words, whether an idea is true depends on what the real world outside us is like, not on what the idea in our mind is like. For example, suppose I want to know whether my idea that it’s raining is true. I can’t find out if that idea is true by just thinking about that idea in my head. No matter how much I examine that idea and think about its qualities in my head, I will not be able to figure out whether it’s true or not. To find out if it’s true, I have to check the real world and see if the rain is actually coming down in the real world outside my head. But Descartes is claiming that just by examining an idea in my head to see if it has the qualities of being “clear” and “distinct” I will be able to tell if it is true. He is claiming that if we see in our head that an idea is “clear” and “distinct” then we can know it is true without checking the real world. Do you think Descartes could be right? Why?