knowledge The powers of mind and body attain their full solidity and vigor, and the character is rounded out into completeness and symmetry.
At last, old age or senility comes creeping slowly on. The faculties gradually lose their vigor and the senses become unretentive. The body demands rest and quiet, and its functions pass into decadence.
LINES OF GROWTH. On three great lines of move
ment we may trace the influence of higher and higher faculties as nations pass through the phases of childhood, youth and maturity. These are the lines of Intellect in the front brain; of Social life in the middle brain, and of Industry in the back brain. Human evolution has meant an increase of knowledge of social or collective life, and of mastery over the forces of nature in the varied fields of industry.
At every upward step these three lines of growth have been closely and vitally dependent upon each other.
This law of interdependence is one of the best established truths in psychology. There can be no valuable or important growth of social life, of morals or religion, without a corresponding growth of knowledge and of industrial conditions. The Affections or social nature must constantly use the intellect in order to perceive, remember and reason about its own objects of love. And the faculties of the will, in the back brain, must be used if we would give any of the impulses or desires of love an outward expression in conduct. Love is the central power, but Wisdom and Will are its constant and essential instruments.
From this law we see that it is utterly vain to hope that we may ever remove the great evils and defects