There is a text for this chapter. It is taken from the works of arguably the most cognitive of English 19th-century poets —Robert Browning. The familiar lines are from the imagined soliloquy of the painter, Andrea del Sarto:

I am about to make that reach. My immodest aim is to move us toward a unifying theory of cognitive development. Whether the effort brings us closer to heaven or to hell remains to be seen. Perhaps the best I can hope for is to be left in limbo; by which I mean that the reader will reserve judgment, pending further developments. And, as becomes apparent here, further developments are indeed required. What I present here is less a theory than a theoretical perspective.