Our Local System of Inhabited Worlds—Evolutionary Planets (Part 4)

The one physical uniformity of mortals is the brain and nervous system; nevertheless, there are three basic organizations of the brain mechanism: the one-, the two-, and the three-brained types.  Urantians are of the two-brained type, somewhat more imaginative, adventurous, and philosophical than the one-brained mortals but somewhat less spiritual, ethical, and worshipful than the three-brained orders.

We begin the reading in Paper 49, Section 5, Item 13.