There are two kinds of work: that which takes place in real time and that which does not. Of the former there are two kinds further: that which requires literal practice and that which requires approximate preparation. "Real time" is another way of specifying direct and determinate causation. Thus the first kind of work takes place in a Newtonian and the second in a Heisenbergian universe. All work requires the mind, but the first kind of work requires the body also.