None can understand it but thinkers, and deep thinkers, and thinkers in the right direction.  Merely to glance around and gather scraps of knowledge from the various, “ologies” in existence, which the “march of intellect” has brought into being, and which were unknown to our forefathers; and then to force them on the young memory at random, may be to teach what was not before taught, but it is not to display any new method of teaching; any more efficient way of communicating knowledge.  Those who would truly understand the infant system, must think for themselves, and observe the workings of the young mind, mark the intellectual principles which first develope themselves, strive to understand the simple laws of mental action; and all this that they may know how to teach in accordance with them.  When this is fairly done, perhaps the whole that is recorded in this book, may be thought more valuable than it is at present, and be found a not unworthy subject to devote a whole life to become acquainted with and elucidate both practically and theoretically.  Others then will, perhaps, not be quite so audacious in unjust plagiarisms.  When Columbus had made the egg stand on an end all others could then do it.  When he had discovered America, every one said they might have done it also.  All great and important truths are simple, and when presented to the mind, although unknown before, seem as if they had been well known, there is such an accurate consistency between the mind and them.  This leads me to suppose that there is simple and useful truths in my volumes, as every one seems to take them for their own.  I can only say that they have cost me many and many an hour of close observation, and deep and independent thinking.  I have devoted my whole life for the good of others, and have injured myself and family, that I might do so.  To rescue little children from vice and misery, and to have them placed under physical, intellectual, moral, and religious discipline, has been the delight of my heart, and the object of my life.  After this labour, to have my inventions pirated, my plans made use of in part, and in the rest spoken against; to have others to reap the fields that I have sown, and at the same time traduce and injure me; to be thus thrust out as it were from my rightful employment, and left in comparative obscurity as old age begins to draw on; requires a spirit stronger than that of man, and a heart more than human, not to feel it, and feel it deeply.  I care little for myself, but regret most to see spurious systems of infant education palmed upon the public by ignorant persons, and thus deprive them of a great benefit which they might possess.