Joel Sadler is right in so far as history has advanced — probably faster than Peter Drucker expected in 1959. However, he is wrong with regard to knowledge work. Drucker argued that scientific management originally invented for manual work has to be applied to knowledge work. Now, the management of knowledge work Drucker had in mind in 1959 has been so successful that people like Sadler not even recognize the value knowledge work still has. The main reason is that he makes no difference between knowledge and information.