"Some distinguished philosophers think that boys' eyes should be taught or trained to the examination of objects: in other words, that boys should be taught to observe things and to see likeness and difference. It is done to some extent by all boys: their games teach them something, and they know a cake from an apple. But the power of careful, patient looking at a thing is not fully acquired without some pains on the part of a teacher. When a boy reads aloud, he must look carefully at the words and letters, or he will blunder. This is an instance of observation. But the philosophers mean, I believe, that we should introduce certain things called sciences into school teaching."