The expression often used by Mr. Herbert Spencer, of the "Survival of the fittest", is more accurate, and is sometimes equally convenient.
A man who dares to waste one hour of time has not discovered the value of life.
Man tends to increase at a greater rate than his means of subsistence.
How paramount the future is to the present when one is surrounded by children.
I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection.
The very essence of instinct is that it's followed independently of reason.