问答题 To speak truly, few adult persons can see nature. Most persons do not see the sun. At least they have a very superficial seeing. The sun illuminates only the eye of the man, but shines into the eye and the heart of the child. The lover of nature is he whose inward and outward senses are still truly adjusted to each other; who has retained the spirit of infancy even into the era of manhood. His intercourse with heaven and earth becomes part of his daily food. In the presence of nature, a wild delight runs through the man, in spite of real sorrows. Nature says, —he is my creature, and maugre all his impertinent grieves, he shall be glad with me. Not the sun or the summer alone, but every hour and season yields its tribute of delight; for every hour and change corresponds to and authorizes a different state of the mind, from breathless noon to grimmest midnight. Nature is a setting that fits equally well a comic or a mourning piece. In good health, the air is a cordial of incredible virtue. Crossing a bare common, in snow puddles, at twilight, under a clouded sky, without having in my thoughts any occurrence of special good fortune, I have enjoyed a perfect exhilaration. Almost I fear to think how glad I am. In the woods too, a man casts off his years, as the snake his slough, and at what period soever of life, is always a child. In the woods is perpetual youth. Within these plantations of God, a decorum and sanctity reign, a perennial festival is dressed, and the guest sees not how he should tire of them in a thousand years. In the woods, we return to reason and faith. There I feel that nothing can befall me in life, —no disgrace, no calamity,(leaving me my eyes,)which nature cannot repair. Standing on the bare ground, —my head bathed by the blithe air, and uplifted into infinite space, —all mean egotism vanishes. I become a transparent eye-ball. I am nothing. I see all. The currents of the Universal being circulate through me; I am part or particle of God. The name of the nearest friend sounds then foreign and accidental. To be brothers, to be acquaintances,—master or servant, is then a trifle and disturbance. I am the lover of uncontained and immortal beauty. In the wilderness, I find something more dear and connate than in streets or villages. In the tranquil landscape, and especially in the distant line of the horizon, man beholds somewhat as beautiful as his own nature.

问答题 a. Identify the author and the work from which the passage is selected.

问答题 b. Explain the sentence "The sun illuminates only the eye of the man, but shines into the eye and the heart of the child. "

问答题 c. What kind of philosophical school does the author belong to? And define the term.