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.