Having seen the development of Shepard's program at close hand, I have been inspired by the sophistication of his results. However, his program deals with only half of what is needed: Shepard's research tells what the perception/cognitive process is about, it does not tell how that process is implemented. True, Shepard has recourse to the “how” of process in evolution, but that is not the “how” of everyday implementation. For that we need to know the brain processes with which we can implement Shepard's insights. [Shepard]