One of the strange things about living in the world is that it is only now and then one is quite sure one is going to live forever and ever and ever. One knows it sometimes when one gets up at the tender solemn dawn-time and goes out and stands alone and throws one's head far back and looks up and up and watches the pale sky slowly changing and flushing and marvelous unknown things happening until the East almost makes one cry out and one's heart stands still at the strange unchanging majesty of the rising of the sun—which has been happening every morning for thousands and thousands and thousands of years. One knows it then for a moment or so...And it was like that with Colin when he first saw and heard and felt the Springtime inside the four high walls of a hidden garden. That afternoon the whole world seemed to devote itself to being perfect and radiantly beautiful and kind to one boy. Perhaps out of pure heavenly goodness the spring came and crowned everything it possibly could into that one place.
 

The narrator's extended meditation on the feeling that one is going to live forever reveals that Hodgson Burnett is drawing heavily upon the work of Immanuel Kant (a German philosopher of the Enlightenment) in establishing the feeling's source. The narrator says that one may have this sense that one will live forever when one looks at a sunset; when one stands in a deep wood; when looks up at the immense night sky. Tellingly, all of these examples are drawn from nature. Kant, in his book Critique of Judgment, said that one will often, when confronted with a truly immense natural landscape (his examples include the ocean and a mountain) have a feeling he called "sublime." This sublime feeling occurs because the hugeness of the landscape implies the hand of God. In regarding it, we realize that there is a force and intelligence infinitely larger than our own behind the composition of the world. Thus, the experience of nature provides Burnett's children with a realization that they are going to live forever because it assures them of the presence of God: if the Christian God exists, then eternal life exists.