This beautiful approach was developed in 1900 by the first Italian woman doctor, Dr. Maria Montessori. After finishing her medical school she took an opportunity to work with children with learning difficulties. This was the start of her lifelong journey in education. She had not looked back ever since.
She observed that young children in the mental facility were hungry for sensory stimulation. She then developed some learning aparatuses, and the feedback from the children shook her world. These children, so-called mentally disabled, were actually working and learning from them.
Although the philosophy is over a hundred years old, it is still considered to be new in education.