Part 1 in this four-part series of articles discussed Piaget's theories of learning and development (Crossland, 2016). Part 2 explores how post-Piagetian researchers have addressed criticisms of Piaget's theories by linking recent evidence including that from neuroscience. The outcomes show that good teachers make a difference by implementing classroom-based optimal learning strategies. This new evidence brings Piaget's theories into the 21st century and leads to a clearer definition of optimal learning in the classroom.