Building a better mousetrap merely results in smarter mice.

Nothing can be more improving to a young naturalist, than a journey in a distant country.

I would give absolutely nothing for the theory of Natural Selection, if it requires miraculous additions at any one stage of descent.

But when on shore, & wandering in the sublime forests, surrounded by views more gorgeous than even Claude ever imagined, I enjoy a delight which none but those who have experienced it can understand.

Wherever the European has trod, death seems to pursue the aboriginal.

I can indeed hardly see how anyone ought to wish Christianity to be true for if so the plain language of the text seems to show that the men who do not believe, and this would include my father, brother and almost all of my friends, will be everlastingly punished. And this is a damnable doctrine.

The lower animals, on the other hand, must have their bodily structure modified in order to survive under greatly changed conditions. They must be rendered stronger, or acquire more effective teeth or claws, in order to defend themselves from new enemies; or they must be reduced in size so as to escape detection and danger. When they migrate into a colder climate they must become clothed with thicker fur, or have their constitutions altered. If they fail to be thus modified, they will cease to exist.