"It is curious why anybody should pooh-pooh a study of fossils or various forms of rocks or lava. Such things grant us our only vision into Natural History's big book; and it isn't a book in first-class condition. Far from it! Just a tiny scrap; a slip; or, possibly a big chunk is found, with nothing notifying us as to how it got to that particular point, nor how long ago. Man can only look at it, lift it, rap it, cut into it, and squint at it through a magnifying glass. And,—think about it. That's all; until a formal study brings accompanying thoughts from many minds; and, by such tactics, judging that in all probability such and such a rock or fossil footprint is about so old. Natural History holds you in its grasp through just this impossibility of finding actual facts; for it is thus causing you to think. Now, thinking is not only a voluntary function; it is an acquisition; an art. Plants do not think. Animals probably do, but in a primary way, such as an aid in knowing poisonous foods, and how to bring up an offspring with similar ability. But Man can, and should think, and think hard and constantly. It is ridiculous to rush blindly into an action without looking forward to lay out a plan. Such an unthinking custom is almost a panic, and panic is but a mild form of insanity."