The essence of all pantheism, evolutionism, and modern cosmic religion is really in this proposition: that Nature is our mother. Unfortunately, if you regard Nature as a mother, you discover that she is a step-mother. The main point of Christianity was this: that Nature is not our mother; nature is our sister. We can be proud of her beauty, since we have the same Father; but she has no authority over us; we have to admire, but not to imitate. This gives to the typically Christian pleasure in this earth a strange touch of lightness that is almost frivolity. Nature was a solemn mother to worshipers of Isis and Cybele. Nature was a solemn mother to Wordsworth or to Emerson. But Nature is not solemn to Francis of Assisi or to George Herbert. To St. Francis, Nature is sister, and even a younger sister: a little, dancing sister, to be laughed at as well as loved.