At the outset of an inquiry how far existing facts ought to be allowed to overrule ideas and principles that are at variance with them, a preliminary question lies in our way, about which it may be well to say something. This is the question of a dual doctrine. In plainer words, the question whether it is expedient that the more enlightened classes in a community should upon system not only possess their light in silence, but whether they should openly encourage a doctrine for the less enlightened classes which they do not believe to be true for themselves, while they regard it as indispensably useful in the case of less fortunate people. An eminent teacher tells us how after he had once succeeded in presenting the principle of Necessity to his own mind in a shape which seemed to bring with it all the advantages of the principle of Free Will, he 'no longer suffered under the burden so heavy to one who aims at being a reformer in opinions, of thinking one doctrine true, and the contrary doctrine morally beneficial.'[5] The discrepancy which this writer thought a heavy burden has struck others as the basis of a satisfactory solution. Nil dulcius est bene quam munita tenere Edita doctrina sapientum templa serena, Despicere unde queas alios passimque videre Errare atque viam palantes quaerere vitae. The learned are to hold the true doctrine; the unlearned are to be taught its morally beneficial contrary. 'Let the Church,' it has been said, 'admit two descriptions of believers, those who are for the letter, and those who hold by the spirit. At a certain point in rational culture, belief in the supernatural becomes for many an impossibility; do not force such persons to wear a cowl of lead. Do not you meddle with what we teach or write, and then we will not dispute the common people with you; do not contest our place in the school and the academy, and then we will surrender to your hands the country school.'[6] This is only a very courageous and definite way of saying what a great many less accomplished persons than M. Renan have silently in their hearts, and in England quite as extensively as in France. They do not believe in hell, for instance, but they think hell a useful fiction for the lower classes. They would deeply regret any change in the spirit or the machinery of public instruction which would release the lower classes from so wholesome an error. And as with hell, so with other articles of the supernatural system; the existence of a Being who will distribute rewards and penalties in a future state, the permanent sentience of each human personality, the vigilant supervision of our conduct, as well as our inmost thoughts and desires, by the heavenly powers; and so forth.