So in the childhood world. As I said, anything may happen. But you will note, beautiful, sunny, lovely as this childhood world is as a phase of experience, as a stage of development, sweet as may be the memory of it, yet, if the child is ever to grow to manhood, is ever to be anything, ever to do anything, it must outgrow this Jack-and-the- Beanstalk world, this Santa Claus world, this world in which anything may happen, and must begin to doubt, begin to question, begin to test things, to prove things, find out what is real and what is unreal, what is true and what is untrue, must measure itself against the realities of things, learn to recognize the real forces and the laws according to which they operate, so as to deal with them, obey them, make them serve him, enable him to create character and to create a new type of civilization, new things on the face of the earth.

Now what is true of each individual child has been true of the race. The world started in childhood; and for thousands of years it believed very easily, it believed altogether too much for its good, it believed altogether too readily. Naturally, perhaps, necessary in that stage of its development; but so long as it remained in that stage there was no possibility of its becoming master of the earth.

Note, for example, the state of mind of the old Hebrews, I use them merely as an illustration, because you are familiar with their story as told in the Old Testament. Similar things are true of every race on the face of the earth. They knew nothing about the real nature of this universe. They knew nothing about natural forces working in accordance with what we call natural laws. Consequently, they lived in a child- world, a world of magic and miracle, a world in which anything might happen. It did not trouble one of the people of that time to be told that, in answer to the prayer of one of the prophets, an axe-head which had sunk in the water rose and floated on the surface. There were no natural laws in his mind contradicted by an asserted fact like that. It never occurred to him to be troubled about it. There was nothing very startling to him in being told that the sun stood still for an hour or two to enable a general to finish a battle in which he was engaged. He did not know enough about the universe to see what tremendous consequences would be involved in the possibility of a thing like that. He was not troubled when you told him that a man had been swallowed by a great fish, and had lived for three days and three nights in its stomach, and had come out uninjured. There was no improbability in it to him. Simply, a question as to whether God had chosen to have the fish large enough so that it could swallow him. To be told again that a human body that could eat food and digest it, a body like ours, might rise into the air and pass out of sight into some invisible heaven, not very far away, there was nothing incredible about it. He knew nothing about the atmosphere, limited in its range so that it would be impossible to breathe beyond a certain distance from the planet. He knew nothing about the intense cold that would make life impossible just a little way above the surface.

The world in which our forefathers lived until modern times was just this magic, Jack-and-the-Beanstalk world, a world without any impossibilities in it, without any improbabilities in it. All this thought of the true and the untrue, the possible and the impossible, the probable and the improbable, is the result of the fact that man has grown up, has left his childhood behind him, has begun to think, has begun to study, has begun to search for reality, to find out the nature of the world in which he lives, the forces with which he must deal, to understand the universe at least in some narrow range, measured by his so-far experience.

The world, then, until modern times has believed too readily, has accepted things too easily. Let us note, for example, what have been called by way of pre-eminence the Ages of Faith, the Middle Ages, the age, say, from the seventh or eighth century until the thirteenth or fourteenth. What was characteristic of those ages? Were they grand, noble? They were ages of ignorance, of superstition, of cruelty, of immorality, of poverty, of tyranny, of degradation. Almost everything existed that men would no longer bear to-day; and hardly any of the grand things that characterize modern civilization had then been heard of.

Where did this modern civilization of ours begin? Did it ever occur to you that it began when men began to doubt? It began, we say, with the Renaissance. What was the Renaissance? The Renaissance was the birth of doubt, the birth of question, the demand on the part of men, who began to wake up and think, for evidence. It was the beginning of the scientific age, the birth of the scientific spirit which has renovated, re- created, uplifted the world. Men began to think, to look about them, and to prove all things. And instead of holding fast all things, as they had been doing in the past, they began to hold fast only the things which they found by experience, and after testing and trial, to be good.

Here began, then, the civilization of the world; and all that is finest and highest in industry, in education, in discovery, in the whole external civilization of the world, came in with the coming of this spirit that questions and that asks for proof.

I do not wish you to understand me as supposing that all kinds of doubt are good, equally good. The Church, as I said a little while ago, has been accustomed to teach us that doubt was wrong; and there are certain kinds of doubt that are morally wrong, certain kinds of doubt that are disastrous to the highest and finest life of the world.

I wish now to analyze a little and define and make clear these distinctions, that you may see the kind of doubt which is evil and the kind of doubt which is good.

There are doubts which spring out of the fact that men, under the influence of personal interest, as they suppose, or strong desire, wish to follow certain courses, wish to walk in certain paths; and they doubt and question the laws, moral or mental, religious or what not, which stand in their way, which would prohibit their having their will. As an illustration of what I mean, suppose a man is engaged in a certain kind of business, or wishes to manage his business in a certain kind of way. He suspects, if he stops and thinks about it, that the interests of other people may be involved, that the way in which he wants to conduct his business is a selfish way, that the interests of other people may be injured, that the world as a whole may not be as well off; but it seems to be for his own advantage.