Herbert Spencer was a smart man who lived a long time ago. He was very interested in how people and animals are different and how they all work together. Mr. Spencer thought a lot about how everyone has to do their own thing and not worry about what other people are doing.
He made up an idea called "survival of the fittest." This means that animals or people who are the strongest and best at what they do will survive and be successful. Mr. Spencer thought that this was true not only for animals but also for people.
Mr. Spencer wrote a lot of books and talked about his ideas to other people. Some people agreed with him and some people didn't, but he always thought it was important to think for yourself and not just believe what everyone else believes.
In summary, Herbert Spencer was a very smart man who had ideas about how animals and people work together. He believed that the strongest and best at what they do will survive and succeed.