MAN'S mind may be likened to a garden, which may be intelligently cultivated or allowed to run wild; but whether cultivated or neglected, it must, and will, bring forth. If no useful seeds are put into it, then an abundance of useless weed-seeds will fall therein, and will continue to produce their kind.
Just as a gardener cultivates his plot, keeping it free from weeds,and growing the flowers and fruits which he requires, so may a man tend the garden of his mind, weeding out all the wrong, useless, and impure thoughts, and cultivating toward perfection the flowers and fruits of right, useful, and pure thoughts. By pursuing this process, a man sooner or later discovers that he is the master-gardener of his soul, the director of his life. He also reveals, within himself, the laws of thought, and understands, with ever-increasing accuracy, how the thought-forces and mind elements operate in the shaping of his character, circumstances, and destiny.
(few lines from "As a Man Thinkth")