When we hear the word “invention”, what first comes to mind are practical inventions – those that make our lives easier. We often forget about abstract inventions, which determine and guide our lives even more than the former. They are used to describe the world in order to better understand it. With their help, we can invent increasingly complex concrete inventions. 50 Abstract Inventions describes 50 fundamental concepts used on a daily basis to describe, understand and control the world. The book presents an important and challenging subject matter to young readers. It is a product of the author’s long-time work in the field of philosophy of science and is intertwined with her experience in analysing educational children’s and young adult books.