Brand Blanshard was a really smart man who lived a long time ago. He studied and wrote about philosophy, which is a way of thinking about big questions like how we know things and what makes things good or bad.
Blanshard believed that you can't just believe something because someone else told you it was true. You have to think about it and make sure it makes sense to you. He also believed that things are good or bad based on how they help or harm people, not just whether they make you happy or sad.
Blanshard wrote lots of books that helped other people think more deeply about philosophy too. He was really good at explaining complicated ideas in a way that everyone could understand, even kids like you!