How important is a constant intercourse with nature and the contemplation of natural phenomena to the preservation of moral and intellectual health!

The eye which can appreciate the naked and absolute beauty of a scientific truth is far more rare than that which is attracted by a moral one.

WE begin to die not in our sense or extremities, but in our divine faculties.

You fail in your thoughts, or you prevail in your thoughts only.

To the sick, indeed, nature is sick, but to the well, a fountain of health.

I should consider it a greater success to interest one wise and earnest soul, than a million unwise and frivolous.

None can lead this life who are not almost amphibious.