We believe it is the duty of the head of a household to rear his family in the ideas in which he believes. Whatever solution of the religious problem he may have attained, he ought to hide it from no one, and in especial not from his family. Moreover, even if he should wish to keep his opinions secret, he would be unable to do so, at least for the whole of his life. His dissimulation would simply result in such an association in the minds of his children between moral precepts and religious dogmas that the chances would be that they would stand, or rather fall, together. Of all people in the world the child is precisely the one who is likely to suffer most from a belief that religion and morality are inseparably bound up together. Of all human beings children are least philosophical, least metaphysical, least familiar with scientific ideas, and therefore of all others the most easily biassed once for all by the inculcation of false or doubtful notions presented as certain. In China, at the periodical conferences, certain mandarins dilate upon the following theme in the presence of the more notable among the inhabitants: “Do your duty as a citizen and beware of religion.” That is precisely what a father ought to say again and again to his children. It is a good principle of education to take it for granted that the child is rational, and to treat it as such, in order ultimately and gradually to develop the spirit of reason in it. What a child lacks is much less intensity of attention than continuity. Very often among country people, and almost always among inferior races (as also among animals), the young are more wide-awake, more curious, more quick-minded than the mature men; but their attention must be seized in transit; teaching them resembles teaching a bird on the wing. Their schoolmaster must have the gifts of a bird-fancier; and it is his fault much oftener than the child’s if the latter does not understand, does not ask questions, is inert and incurious. The scientific education of the child should begin with its first question; truth is a debt that one owes to it, and truth accessible to its intelligence. The moment a child asks a question out of its own head, it is at least in part prepared to understand the reply; the duty of the person interrogated is to reply, as fully and as truly as he believes the child capable of understanding, and if he leaves gaps he must at least never fill them with lies. It is so easy to tell the child to wait until it is bigger. There should be no fear of precociously developing the child’s reason in its two essential forms, the instinct of inquiry, of _why_ and _how_, and the instinct of perception, of logical cogency in the reply to the “why” and “how.” One need not be afraid that the child will fatigue its brain by abstract reasoning; Pascals are rare. The danger does not lie in a premature development of the reason, which it is always easy moreover to check, but in a premature development of