The Cambridge University Moral Sciences Club is a group of people who like to talk about what is right and wrong or good and bad. They meet up regularly to have discussions about these ideas and share their thoughts with each other.
Think of it like talking about what you should or shouldn't do, kind of like when you have to decide whether or not it's okay to take a toy from someone else. But these grown-ups talk about more complicated things like ethics, which is what people believe to be right or wrong.
The Club was started a long time ago, in the year 1878, by some students who were interested in discussing moral and ethical issues. Today, it's still going strong and anyone who is interested in the Club's topics can join.
So, it's like a really cool club where people get together to talk about important and interesting ideas that help them figure out what is right and wrong in the world.