I have often held in my hand a black walnut. It has a shell like stone. It has many internal stony reinforcements. But in between is an unimpressive, unimportant-looking meaty substance that has a mysterious and tremendous power. If you plant this seed under certain circumstances, heat is produced inside.
Now, whether it is a seed, or a teacher, or a businessman, or a student, when we begin to heat inside, something begins to happen. Your leaders may put a lot of heat on you from the outside, but that doesn’t always do much good. The heat that does the greatest good is the heat that is generated on the inside. Success, like failure, is an “inside” job.
When this walnut begins to heat inside, it produces a mysterious power that breaks that stony shell as though it were paper, and a little shoot works its way up through the soil to become a great walnut tree. That is, there is some mysterious power inside of a walnut shell that has the ability to attract out of the soil and the air and the water all of the elements necessary to become a great walnut tree—including wood, and foliage, and blossoms, and fragrance, and fruit.