The vertical line separates the more passive and the more active faculties. The posterior half of the brain is the source of the backward forces by which the body is advanced, as the anterior half is the source of the forward movements by which our progress is checked. The posterior half would make blind, unceasing, irrepressible action--the anterior half would produce a state of relaxed and feeble tranquillity and sensibility--the condition of a helpless victim. The concurrence of the two is indispensable to human life, and the necessity of their more or less symmetrical balance is so great that nature balances the head upon the condyles of the occipital bone, at the summit of the neck, which are so located as to correspond very nearly with the opening of the ear. The contour of the head is very nearly that of a semicircle, with its center an inch or more above the cavity of the ear. Thus wisely has nature arranged in well-balanced individuals the symmetrical proportion between the active and passive elements of life. In the head of the writer there is a preponderance of the passive over the active elements, which gives him the attraction to a studious, rather than active or ambitious life.[1] In nations or races of ambitious character, the head is long, or _Dolico-cephalic_, and the occipital measurement is larger than the frontal, but in those of peaceful, unambitious character, like the ancient Peruvian and the Choctaws of the United States, the occipital measurement is less than the frontal. [1] The head of Dr. Gall shows the same frontal preponderance, which led him to the pursuits of intellect instead of ambition, but also shows an immense force of character derived from its extreme breadth and basilar depth. The head of Spurzheim, whose skull I have often examined, shows even a greater preponderance of the front, and a predominance of the coronal over the basilar region, producing his marked amiability, with sufficient basilar breadth to give him physical force. Each had a large brain. In Dr. Wm. Byrd Powell, who had a long head, and who was a man of restless ambition and fiery energy, the occipital predominated over the frontal development decidedly, producing, although the frontal development was not large, much activity and force, or brilliancy of mind, but not the calm temperament most favorable to philosophy. His opinions were more bold and striking than accurate. Dr. P. made a valuable collection of crania, and was almost the only American scientist who gave much attention to the _cultivation_ of phrenology.