to gratify hate, envy, and vengeance, or wanted children, or wanted to prevent other people from having children, this way was always supposed to be open. No doubt very many of them tried it, at least in homely and silly ways—when put to the torture they confessed it. Then, too, somnambulism, dreams, and nightmare took forms which ran on the lines of popular superstition, and many a woman charged with witchcraft did not know but she had been guilty of it to some extent and without conscious knowledge. Again, the Scripture argument for demonism and witchcraft was very strong. It was this pitfall which caught the Protestants; how could they deny that there are any witches when the Bible says: "Thou shalt not suffer a witch to live." Witches were persons who had gone over to the side of Satan and his hosts in their war on God; they were enemies of the human race. The deductions from the primary fantastic notion of demons were all derived on direct and indisputable lines, and those deductions ruled the thought of Christian Europe for five hundred years.
What was wanted to put a stop to the folly and wickedness was criticism. The case shows us that we men, including the greatest and best of us, may fall at any time under the dominion of such a mania, unless we are trained in methods of critical thinking. A series of great sceptics from Montaigne to Voltaire met the witch doctrines with scorn and derision. They were not afraid to deny the existence of demons. It appears also that the so-called common-sense of the crowd revolted at the absurdities of witchcraft. Every person who was executed as a witch named, under torture, others, who were then arrested, tortured, and executed; each of these named others, and so the witch-judges found that they were driven on, by judicial execution of the most cruel form, to depopulate a whole territory. It was a critical revolt when they saw this construction of their own conduct and turned against it. When we read the story we are amazed that good and honest men could have gone on for centuries inflicting torture of the extremest kind on old women without the bit of critical reflection which should have led them to ask themselves what they were doing.
Let us not make the mistake of supposing that all follies and manias of this kind are permanently overcome and need not be feared any longer. The roots of popular error are ineradicable; they lie at the bottom of human nature; they can produce new growth and new fruits at any time. In this twentieth century the probable line on which the deductions will be drawn is in politics and civil institutions. The modern world has rejected religious dogmatism, but it has taken up a great mass of political dogmatism, and this dogmatism is intertwined with the interests of groups of men. If you accept the political dogmas of the eighteenth century and begin to build deductions on them you will reach a construction as absurd and false as that of witchcraft. The only security is the oonstant practise of critical thinking. We ought never to accept fantastic notions of any kind; we ought to test all notions; we ought to pursue all propositions until we find out their connection with reality. That is the fashion of thinking which we call scientific in the deepest and broadest sense of the word. It is, of course, applicable over the whole field of human interests, and the habit of mind which insists on finding realities is the best product of an education which may be properly called scientific. I have no doubt that, in your lifetime, you will see questions arise out of popular notions and faiths, which will call for critical thinking such as has never been required before, especially as to social relations, political institutions, and economic interests.
Here I may notice, in passing, the difference between science and religion in regard to the habits of thought which each encourages. No religion ever offers itself except as a complete and final answer to the problems of life. No religion ever offers itself as a tentative solution. A religion cannot say: I am the best solution yet found, but I may be superseded tomorrow by new discoveries. But that is exactly what every science must say. Religions do not pretend to grow; they are born complete and fully correct and our duty in regard to them is to learn them in their integrity. Hence Galton says that "the religious instructor, in every creed, is one who makes it his profession to saturate his pupils with prejudice."[3]
Every science contains the purpose and destiny of growth as one of its distinguishing characteristics; it must always be open to re-examination and must submit to new tests if such are proposed. Consequently the modes and habits of thought developed by the study of science are very different from those developed by the study of religion. This is the real cause, I think, of the antagonism between science and religion which is vaguely felt in modern times, although the interest is lacking which would bring the antagonism into an open conflict. I cannot believe that this attitude will remain constant. I am prepared to believe that some of you may live to see new interest infused into our traditional religion which will produce an open conflict.[4] At present scientific methods are largely introduced into history, archæology, the comparison of religions, and Biblical interpretation, where their effect is far more destructive than the mass of people yet know. When the antagonism develops into open conflict, parties will take sides. It is evident that the position of the parties on all the great faiths and interests of men will differ very widely and that each position will have to be consistent with the fundamental way of looking at the facts of life on which it is founded. It does not seem possible that a scientist and a sacramentarian could agree about anything.
There is another form of phantasm which is still in fashion and does great harm, that is, faith in ideals. Men who rank as strong thinkers put forward ideals as useful things in thought and effort. Every ideal is a phantasm; it is formed by giving up one's hold on reality and taking a flight into the realm of fiction. When an ideal has been formed in the imagination the attempt is made to spring and reach it as a mode of realizing it. The whole process seems to me open to question; it is unreal and unscientific; it is the same process as that by which Utopias are formed in regard to social states, and contains the same fallacies; it is not a legitimate mental exercise. There is never any correct process by which we can realize an ideal. The fashion of forming ideals corrupts the mind and injures character. What we need to practise, on the contrary, is to know, with the greatest exactitude, what is, and then plan to deal with the case as it is by the most approved means.
Let me add a word about the ethical views which go with the scientific-critical way of looking at things. I have mentioned already our modern view of manufactured documents, which we call forged. In regard to history it seems to me right to say that history has value just on account of the truth which it contains and not otherwise. Consequently the historian who leaves things out, or puts them in, for edifying, patriotic, or other effect, sins against the critical-scientific method and temper which I have described. In fact, patriotism is another root of non-reality, and the patriotic bias is hostile to critical thinking.
It must be admitted that criticism is pessimistic. I say that it must be admitted, because, in our time, optimism is regarded as having higher merit and as a duty; that which is pessimistic is consequently regarded as bad and wrong. That is certainly an error. Pessimism includes caution, doubt, prudence, and care; optimism means gush, shouting, boasting, and rashness. The extreme of pessimism is that life is not worth living; the extreme of optimism is that everything is for the best in the best of worlds. Neither of these is true, but one is just as false as the other. The critical temper will certainly lead to pessimism; it will develop the great element of loss, disaster, and bad luck which inheres in all human enterprises. Hence it is popularly considered to consist in fault-finding. You will need to guard against an excess of it, because if you yield to it, it will lame your energies and deprive you of courage and hope. Nevertheless I cannot doubt that the popular feeling in our time and country needs toning down from a noisy and heedless optimism. Professor Giddings,[5] a few years ago, made a very interesting analysis and classification of books published in this country, from which he thought that he proved, statistically, that the temper of our people now is between ideo-emotional and dogmatic-emotional. By ideo-emotional he means inquiring or curious, and convivial; by dogmatic-emotional he means domineering and austere. We must notice, as limiting this test, that the book-market can bear testimony only to the taste of the "reading public," which is but a very small part of the population, and does not include the masses. Professor Giddings found that 50 per cent of the books published aimed to please and appealed to emotion or sentiment; 40 per cent aimed to convert, and appealed to belief, ethical emotion, or self-interest; 8 per cent aimed to instruct, were critical, and appealed to reason. The other 2 per
