Think while you look.
Every fact valuable.
To know much about things, you must not merely look at them. You must examine them—that is, you must think while you look. You must think what this is for and what that is for. In this way you can find out a great deal for yourselves. You will not merely see that what I and others tell you is true, but you will find out things that no one has told you, and perhaps some things that no one has found out before you. Newton, who found out so many things that men did not before know, always thought about things as he saw them; and so did Franklin, who, as you remember, discovered that lightning is electricity. They began early, when they were children, to think while they looked. They had a habit of doing it. If they had not, they would not have been such discoverers. Though perhaps none of you may ever discover as many things or as great things as they did, any of you may make some discoveries. Though your discoveries may be small ones, they are not to be despised. They will be worth something. Every fact that is found out is of some value. And if you always think while you see and hear, you may find out for yourselves many facts, and some of them may prove to be of great value.
Sometimes a fact that would appear to be of no value turns out to be worth a great deal. Most people would not think that there was much to be learned from a hen’s muddy tracks on a pile of sugar; but, as you remember I told you in Part First, Chapter XXIX., some one observed the fact that the sugar was whitened wherever the tracks were, and thought about this fact; and the result was that moistened clay came to be used in every sugar refinery in whitening sugar.
One that is in the habit of thinking while he looks will find something interesting wherever he goes. He will not be obliged to go to some museum to see wonderful things, but he will find them all about him. In the most common plants and animals, which most people do not think of much, he will see many things to interest and astonish him; and to him the air and the water, and even the stones under his feet, will be full of wonders.
Much to be learned that is not in books.
You see by what I have said that there is a great deal to be learned that is not in books. Indeed, books will not do you much good if they do not wake up in you a disposition to learn more than they tell you. People that know much are not content with learning merely what they find in books, but learn what they can from every body and from every thing. They use books only as helps, and the most of what they know they learn by observing—that is, seeing and thinking upon what they see.
Knowing the reasons of things.
It is very pleasant to know the reasons of things. I have therefore told you in this book, as I have gone along, as much as I could do, why things are as I have described them; but you will remember that I have now and then said about some things that you are not old enough yet to understand them. As you grow older you can learn more and more, and so the things that you will be interested in will be all the time increasing. But, though you may keep on learning all your lives, there are some things that you never can understand. God understands the reasons of every thing, but there are many, very many things that the wisest of men can not explain.
What Newton said about what he knew.