March 12, 1853

in Thoreau’s Journal:

It is essential that a man confine himself to pursuits —a scholar, for instance, to studies —which lie next to and conduce to his life, which do not go against the grain, either of his will or his imagination. The scholar finds in his experience some studies to be most fertile and radiant with light, others dry, barren, and dark. If he is wise, he will not persevere in the last, as a plant in a cellar will strive toward the light. He will confine the observations of his mind as closely as possible to the experience or life of his senses. His thought must live with and be inspired with the life of the body. The deathbed scenes and observations even of the best and wisest afford but a sorry picture of our humanity. Some men endeavor to live a constrained life, to subject their whole lives to their wills, as he who said he would give a sign if he were conscious after his head was cut off, —but he gave no sign. 

Dwell as near as possible to the channel in which your life flows.  A man may associate with such companions, he may pursue such employments, as will darken the day for him.  Men choose darkness rather than light.