George Perkins Marsh

The physical changes wrought by man are often more subtle and insidious than those produced by natural causes.

The earth is a common property, and its resources should be used for the benefit of all humanity.

The duty of man is to cultivate the earth, not to lay it waste.

The earth is a great library, and man is its most assiduous reader.

The physical world is a testament to the wisdom and power of the Creator.

The earth is a common heritage, and its resources should be managed with responsibility and care.

The true end of human existence is not to exploit nature, but to cherish and protect her.

The earth is a great garden, and man is its most privileged gardener.

The physical changes wrought by man are often more far-reaching and irreversible than those produced by natural causes.

The earth is a common property, and its resources should be shared equitably among all people.

Man has too long forgotten that he is a part of nature, and that his destiny is bound up with hers.

The woods were made for the hunters of dreams, the brooks for the fishers of song.

Physical geography, as an element of the education of youth, is one of the most important branches of study.

We are called upon to redeem the pledge implied in the gift of the soil to its present proprietors.

The destruction of forests is the main cause of the erosion of soils.

Nature is not a dead thing; it is a living process.

Human action has modified the face of the earth more than any other force.

The earth is fast becoming an unfit place for any but a master species.

In the future, as in the past, the conservation of natural resources will be the key to human progress.

Forests are the lungs of the earth.