Reading is nothing more than a mechanical invention, imitative of the act of hearing; as writing is a mechanical mode of indicating sounds, and thus becomes a substitute for the art of speaking, and conveying ideas. But there is this material difference between reading and hearing, that in hearing the person giving attention is in a great measure passive, and may, or may not attend as he pleases. He may receive part of what is said, and, as prompted by Nature, he may silently drop all that he cannot easily reiterate. But in the act of reading, the person has both the active and the passive operations to perform. His mind, while he reads, must be actively engaged in decyphering the words of his book, and the ideas are, or should be, by this act, forced upon the observation of the mind at the same time. As long, therefore, as the child is required to read nothing except that which he understands, and to read no more, and no faster, than his mind can without distraction receive and reiterate the ideas which he reads, the act of grouping will be performed with ease, and with evident delight, and the powers of the mind will be healthfully and extensively exercised and strengthened:--But if this simple principle of Nature be violated, the exercise becomes irritating to the child, and most pernicious in its consequences. The neglect of this application of the principle is so common in education, that it usually escapes observation; but on this very account it demands from us here a more thorough investigation. We say then, that this principle is violated when a child is required to read that which it does not, and perhaps cannot understand; and also when he is required to read more, or to read faster, than he is able to reiterate the ideas in his own mind. On each of these cases we shall say a few words, for the purpose of warning and directing the teacher in applying this important principle in education.