There should be less emphasis on right answers and more discussion of open questions, for which no answers are known. Just because there is little discipline in today's schools, it does not follow that when there was discipline, there was also a great deal of learning. The two have little to do with each other. Learning is best accomplished by children when what they are learning interests them, relates to their goals and is fun. There is no reason why we cannot make everything in school enjoyable.
Children are quite apt learners when they really want to know something.
We must create environments in which children are curious. Today's schools are organized by age groups in grades. Because they always have been. This causes us to lose the use of some available teachers, namely the other, more experienced, children. Children can learn from each other and will do better if they were organized by similar interests instead of similar ages.